Solidworks Host File Block Install -

This guide is intended for educational and technical troubleshooting contexts. It explains a common method used to prevent SolidWorks from “phoning home” to validate licenses or check for updates during a specific installation workflow.

Block SolidWorks license/activation servers (example only)

127.0.0.1 license.solidworks.com 127.0.0.1 solidworks.com 127.0.0.1 sw.install.solidworks.com 127.0.0.1 activation.solidworks.com 127.0.0.1 register.solidworks.com 127.0.0.1 log.solidworks.com

Note: The exact domains change over time and depend on your SolidWorks version. Network monitoring is needed to find all current endpoints.

Instructions

Locate the Hosts File:
- Navigate to: C:\Windows\System32\drivers\etc\
- Find the file named hosts.
Edit the File:
- Open the hosts file using Notepad (Run Notepad as Administrator to ensure you can save changes).
- Go to the bottom of the file.

Add Server Entries:

Copy and paste the following lines at the end of the file. These block the primary activation servers.

127.0.0.1   sw_activation_solidworks_dongle.ems.norman.no
127.0.0.1   sw_dongle_solidworks.ems.norman.no
127.0.0.1   sw_activation_server_solidworks_dongle.ems.norman.no
127.0.0.1   sw_activation_server_solidworks_dongle.noi.no
127.0.0.1   sw_activation_solidworks_dongle.noi.no
127.0.0.1   sw_dongle_solidworks.noi.no
127.0.0.1   www.solidworks.com
127.0.0.1   activation.solidworks.com

Save and Close:
- Save the file (Ctrl + S). If you cannot save, ensure you opened Notepad as Administrator.
- Flush your DNS cache by opening Command Prompt and typing ipconfig /flushdns.

Disclaimer: Modifying system files to bypass software licensing is a violation of the SOLIDWORKS Terms of Use. This information is provided for educational and troubleshooting purposes regarding network configuration only.

Title: A Reliable Workaround for Installation Issues, But Not a Silver Bullet

Rating: ⭐⭐⭐⭐ (4/5)

The Bottom Line: Editing the host file to block SolidWorks server connections is a highly effective method for resolving specific installation hang-ups and "cannot connect to server" errors, particularly for standalone installations or network license issues. However, it is technically a workaround rather than an official fix, and it requires precise syntax to avoid breaking the installation entirely.

Pros:

Solves the "Infinite Spin": Successfully resolves the common issue where the installation manager hangs indefinitely while trying to "retrieve product information" from SOLIDWORKS servers.
Bypasses Server Outages: Useful when SOLIDWORKS activation servers are temporarily down or experiencing regional connectivity issues.
No Third-Party Software: Unlike "stress relief" tools often found on forums, this method uses built-in OS functionality (the hosts file), making it cleaner and safer.

Cons:

Breaks Automatic Updates: By blocking the domains, the SolidWorks Installation Manager can no longer check for updates or service packs. You must download full installers manually from the customer portal.
Syntax Sensitive: A common mistake is forgetting that one wrong IP entry or missing # comment can cause the license manager to fail entirely.
Antivirus Flags: Some aggressive antivirus software (and SolidWorks' own telemetry) may detect the host file modification as "suspicious activity" and block the install anyway.

Detailed Experience: I utilized the host file block method during a fresh install of SolidWorks 2024 on a high-security corporate network. The standard installation manager failed repeatedly at the "Initializing" stage due to firewall restrictions blocking callbacks to swdm.solidworks.com and activation.solidworks.com.

By mapping these domains to 127.0.0.1 in the Windows etc/hosts file, the installation manager immediately skipped the online check and allowed the install to proceed from local files.

Crucial Tip for Users: If you are using this method for a Network License (SNL) setup, be extremely careful not to block your internal license server address. Only block the external SOLIDWORKS validation addresses. Additionally, remember to remove the entries from the host file after the installation is complete if you want the software to successfully validate the license upon the first launch.

Final Verdict: This is a necessary skill for any IT admin managing SolidWorks deployments in restricted environments. It is not a "fix-all" for every installation error, but for connectivity-related stalls, it works 100% of the time. Just remember to undo the changes post-install to ensure your license validation remains healthy.

Manually editing the Windows Hosts file is a common troubleshooting step for SOLIDWORKS

to resolve communication issues between a client computer and a server, especially for (Product Data Management) or (SolidNetWork License Manager).

This is typically used when a DNS (Domain Name System) fails to correctly translate a server's hostname into its IP address, which can block the installation or activation of the software. GoEngineer When to Use a Hosts File Workaround You might need to modify your hosts file if: SOLIDWORKS Installation Manager cannot connect to download or activation servers. fails to connect to the Archive or Database server. You are in a multi-site environment

where servers must communicate across different network domains via VPN.

A "ping" test to the server's name fails, but pinging its IP address works. Dassault Systèmes How to Configure the Hosts File

The hosts file acts as a local "address book" that Windows checks before asking a DNS server. Open Notepad as Administrator : Search for , right-click it, and select Run as Administrator Open the File : In Notepad, go to File > Open . Navigate to the path: C:\Windows\System32\drivers\etc\

Note: You must change the file type filter in the bottom-right of the Open dialog from "Text Documents ( "All Files ( to see the hosts file.* Add Server Info

: Add a new line at the bottom of the file following this format: [Server IP Address] [Server Hostname] 192.168.1.50 MyPDMVaultServer : Save the file and close Notepad. GoEngineer Other Common Installation Blocks If you are seeing a blank white screen

in the Installation Manager (which often looks like a block), it is usually caused by Windows blocking extracted HTML files. : Navigate to \sldim\lang\english\HTML\ in your installation folder. Right-click frameset.html Properties , and click if the button is visible. MLC CAD Systems Summary Table: Resolution Methods Potential Cause Primary Fix Server Connection Failed DNS resolution failure Add IP/Hostname to Hosts file Blank Install Screen Windows security blocking HTML frameset.html in properties Multi-site PDM Issues Cross-domain communication Standardize name resolution in Hosts file

For more detailed technical walkthroughs, you can refer to resources from GoEngineer Javelin Technologies troubleshooting a specific error message you're seeing during the SOLIDWORKS install?

Blocking SolidWorks Installation using Host File

The hosts file is a system file that maps hostnames to IP addresses. It is used by the operating system to resolve hostnames to IP addresses, allowing users to access websites and other network resources. However, the hosts file can also be used to block access to specific websites or servers, including those used by software installation processes.

In the case of SolidWorks, a popular computer-aided design (CAD) software, the installation process may be blocked by modifying the hosts file. This can be useful in environments where SolidWorks is not allowed to be installed or used, such as in a company with strict software usage policies.

How to block SolidWorks installation using the hosts file

To block the SolidWorks installation using the hosts file, follow these steps:

Locate the hosts file: The hosts file is usually located in the following directory: C:\Windows\System32\drivers\etc\hosts on Windows.
Open the hosts file: Open the hosts file with a text editor, such as Notepad, and add the following line at the end of the file: 127.0.0.1 solidsystems.com (or any other SolidWorks-related domain).
Save the changes: Save the changes to the hosts file.

What happens when you block SolidWorks installation

When you modify the hosts file to block SolidWorks installation, the following occurs:

When a user attempts to install SolidWorks, the installation process will try to connect to the SolidWorks servers to validate the license and download necessary files.
However, due to the modified hosts file, the connection will be redirected to the local machine (127.0.0.1), causing the installation to fail.

Workarounds and limitations

While blocking SolidWorks installation using the hosts file can be effective, there are some workarounds and limitations to consider:

Administrative privileges: Users with administrative privileges may be able to modify or delete the hosts file entry, allowing them to install SolidWorks.
Alternative installation methods: Some users may be able to install SolidWorks using alternative methods, such as a local installation package or a different license server.

In conclusion, modifying the hosts file can be a simple and effective way to block SolidWorks installation on a computer or network. However, it is essential to consider the potential workarounds and limitations to ensure that the desired level of control is achieved.

🛠️ Troubleshooting: SOLIDWORKS Installation Blocked by Hosts File

If you are seeing errors like "Could not connect to the SOLIDWORKS server" or the Installation Manager hangs during the pre-check, your Windows hosts file might be blocking essential communication. Why is this happening?

The hosts file is used by Windows to map specific hostnames to IP addresses. Sometimes, security software or previous manual edits add entries that "blackhole" (redirect to 127.0.0.1) SOLIDWORKS licensing or update domains, preventing the installer from verifying your serial number. How to Fix It:

Locate the File: Open File Explorer and go to:C:\Windows\System32\drivers\etc\

Open as Admin: Right-click hosts and open it with Notepad (ensure you run Notepad as an Administrator, or you won't be able to save).

Identify Blocks: Look for any lines containing solidworks.com or im-ak.solidworks.com. Example of a blocked line: 127.0.0.1 im-ak.solidworks.com solidworks host file block install

Clean Up: Delete those lines or add a # at the beginning of the line to comment them out.

Save & Flush: Save the file. Then, open Command Prompt and type ipconfig /flushdns to clear your cache.

Pro-Tip: If the installer still fails, ensure your firewall isn't doing the same job the hosts file was doing! You can also manage background updates through the SOLIDWORKS Installation Manager to ensure everything is running smoothly.

The Digital Drawbridge: On Blocking SolidWorks via the Hosts File

In the world of computer-aided design (CAD), Dassault Systèmes’ SolidWorks stands as a colossus. However, for students, hobbyists, and professionals on a tight budget, its substantial licensing cost often presents a formidable barrier. This financial reality has given rise to a common, albeit legally ambiguous, technical workaround: modifying the Windows Hosts file to block the software’s internet access during installation. This practice, often called "cracking" or "patching," is a deliberate act of digital isolation—a modern drawbridge raised against the manufacturer’s license servers.

The mechanism is deceptively simple. The Hosts file is a local plain-text file that maps domain names to IP addresses before the computer queries external Domain Name System (DNS) servers. By editing this file, a user can redirect SolidWorks’ validation domains (e.g., solidworks.com or specific sw.activation servers) to the local loopback address 127.0.0.1. Consequently, when the installed SolidWorks application attempts to "phone home" to verify its license key, it finds only itself. The connection fails, and the software, believing the server is unreachable rather than blocked, proceeds to run in an offline, activated state.

From a purely functional standpoint, the method is effective. It allows a user to bypass the online check that would otherwise reject an unlicensed key or a key generated by a keygen. For educational environments or individuals learning the software for career advancement, the allure is obvious: full, unrestricted access to a professional tool without the multi-thousand-dollar price tag. It creates a frictionless learning environment, free from the 30-day trial pop-ups or the feature restrictions of the free student edition.

However, the consequences are multifaceted. Legally, this act violates the Digital Millennium Copyright Act (DMCA) in the US and similar laws globally, specifically the clause against circumventing copyright protection systems. Ethically, it deprives developers of revenue that funds ongoing development, bug fixes, and security patches. Furthermore, blocking the Hosts file is a static defense. It prevents legitimate software updates, which require server authentication, leaving the installation vulnerable to unfixed exploits. It also triggers false-positive alarms in antivirus software, as malware often uses the same technique to hide its own command-and-control traffic.

In conclusion, editing the Hosts file to block SolidWorks is a powerful demonstration of the user’s technical control over their own machine—a local veto over a software vendor’s remote oversight. Yet, it is a fragile and illegitimate peace. The user gains a fortress of free functionality, but at the cost of legal safety, software integrity, and moral high ground. For learning, free alternatives like FreeCAD or Onshape offer a legitimate path, while for production, the licensing cost is ultimately the price of admission to a reliable, supported, and professional ecosystem. The blocked Hosts file is not a solution; it is a temporary, high-risk truce in the perennial war between software access and software value.

Blog Post: How to Fix SolidWorks Installation Blocks via the Hosts File

Installing SolidWorks should be straightforward, but sometimes security settings or network glitches can bring your progress to a halt. One common culprit is your computer’s hosts file, which may be blocking the installer from reaching critical activation servers or local network repositories. Why the Hosts File Matters

The Windows hosts file acts like a local phonebook, mapping hostnames to IP addresses before your computer even checks the internet. If this file contains incorrect entries or is locked by security software, the SolidWorks Installation Manager may fail to connect, leading to blank screens or "Installation Failed" errors. Step-by-Step: How to Unblock Your Install

If you suspect your hosts file is causing issues, follow these steps to clean it up or add necessary workarounds:

Open Notepad as Administrator: Search for Notepad in your Start menu, right-click it, and select Run as Administrator.

Navigate to the File: In Notepad, go to File > Open. Navigate to C:\Windows\System32\drivers\etc\. Make sure to change the file type filter from "Text Documents" to "All Files" to see the hosts file.

Check for Blocks: Look for any lines that don't start with a #. Specifically, look for entries related to "SolidWorks" or "Dassault" that might be redirecting traffic to 127.0.0.1 (localhost), which effectively blocks the connection.

Add a Server Workaround (Optional): If you are installing from a network license or PDM server and the DNS is failing, add a new line at the bottom: [Server IP Address] [TAB] [Server Name].

Save and Flush DNS: Save your changes in Notepad. Then, open a Command Prompt and type ipconfig /flushdns to ensure Windows recognizes the updates immediately. Still Blocked?

If you can’t even edit the file, your antivirus (like SentinelOne or Webroot) might be locking it. Temporarily disable your security software or check for "Host File Protection" settings to allow the modification.

If your Installation Manager still shows a blank screen even after checking the hosts file, try this quick fix for blocked HTML files:

The SOLIDWORKS Installation Manager or 3DEXPERIENCE Launcher can be blocked if it lacks permission to modify the Windows hosts file

or if security software prevent access to it. This often results in "Permission Denied" errors or connectivity issues where the installer cannot reach the required license or download servers. SOLIDWORKS Forums Troubleshooting Hosts File Blocks

If your installation is failing due to hosts file issues, follow these steps to resolve the block: Disable Antivirus Interference

: Many antivirus programs (such as Webroot, ZoneAlarm, or SentinelOne) actively "lock" the hosts file to prevent malware from hijacking it.

: Uncheck "Prevent any program from modifying the HOSTs file". : Go to Advanced Settings and uncheck "Lock Hosts File". Check File Attributes : Ensure the hosts file itself is not set to "Read-only". Navigate to C:\Windows\System32\drivers\etc Right-click the file and select Properties Run as Administrator

: The installer requires elevated permissions to write to system files. Right-click your and select Run as Administrator Manual DNS Workaround

: If the installer still cannot connect to license servers, you may need to manually add the server's IP and name to the hosts file. as an Administrator. Open the file at C:\Windows\System32\drivers\etc\hosts Add a new line with the [IP Address] [Server Name] 192.168.1.100 MyPDMServer Save the file and run ipconfig /flushdns in a Command Prompt. SOLIDWORKS Forums Other Common "Blocks" Sometimes the installer appears "blocked" (e.g., a blank white screen

) not because of the hosts file, but because Windows has blocked the downloaded installation files. Unblock Zip/Exe : Right-click the downloaded SOLIDWORKS zip or Properties , and click the button at the bottom. Firewall Exceptions

: Ensure your firewall allows outbound TCP connections on port 80 for sldimdownloader.exe www.javelin-tech.com Are you seeing a specific error code like "Permission Denied" or a blank screen when the installer launches?

Windows hosts file entries mapping SOLIDWORKS domains to 127.0.0.1 can block license activation, requiring users to remove these lines and flush the DNS cache to resolve installation issues. If issues persist, verifying Windows Firewall ports 25734 and 25735, disabling antivirus protection, or utilizing the Product Activation Wizard for email activation can bypass further restrictions. Read the full guide at Logical Solutions logicalsolutions.in How to Install SOLIDWORKS - Logical Solutions

Blocking specific host addresses is a common method for troubleshooting network licensing issues or preventing unwanted communication during a SOLIDWORKS installation. This is typically done by editing the Windows hosts file to redirect hostnames to a non-existent or local IP address. 1. Access the Windows Hosts File

The hosts file is a protected system file. You must use an administrator account to modify it. Open the Start Menu and type Notepad. Right-click Notepad and select Run as Administrator. In Notepad, go to File > Open.

Navigate to the following directory: C:\Windows\System32\drivers\etc\.

Change the file type filter in the bottom-right corner from "Text Documents (.txt)" to **All Files (.*)** to see the hosts file. Select the file named hosts (no extension) and click Open. 2. Add Block Entries

To "block" a hostname, you map it to 0.0.0.0 or 127.0.0.1 (the local loopback address), which prevents the computer from reaching the actual server.

Scroll to the bottom of the file, past any lines starting with #. Add a new line for each address you want to block. Format: [IP Address] [Hostname]

Example to block a specific server: 0.0.0.0 im.solidworks.com Example for local licensing: 127.0.0.1 [Your_Server_Name]. Save the file (Ctrl + S) and close Notepad. 3. Apply Changes (Flush DNS)

After saving the file, you must clear your computer's DNS cache so it recognizes the new rules immediately. Open the Command Prompt (type cmd in the Start menu).

Type the following command and press Enter:ipconfig /flushdns. 4. Troubleshooting Common Blocks

If the installation still fails or communication persists, check these common hurdles:

Antivirus Interference: Some security software (e.g., ZoneAlarm, Webroot) specifically locks the hosts file to prevent unauthorized changes. You may need to disable "Lock Hosts File" in your antivirus settings.

Read-Only Attribute: If you cannot save the file, right-click the hosts file in File Explorer, select Properties, and ensure Read-only is unchecked. This guide is intended for educational and technical

Firewall Rules: For license manager issues, blocking the host file may not be enough; you might need to create inbound/outbound rules in Windows Defender Firewall for ports 25734 and 25735.

Blank Installer Screen: If the installer window is white/blank, this is usually caused by Windows blocking HTML files in the installation media. Right-click the installation folder or setup.exe and select Unblock in the Properties menu. How to Configure the SOLIDWORKS PDM Local HOSTS file

This report outlines technical issues and resolutions related to the Windows "hosts" file and file blocking during SOLIDWORKS installations.

Technical Report: SOLIDWORKS Installation & Host File Issues 1. Hosts File Intervention

The Windows hosts file (C:\Windows\System32\drivers\etc\hosts) is often a point of failure or a necessary workaround during installation and licensing.

Security Software Blocking: Antivirus programs like SentinelOne, Webroot, and ZoneAlarm frequently prevent the SOLIDWORKS launcher from writing to the hosts file.

Resolution: Users must manually uncheck "Prevent any program from modifying the HOSTs file" (Webroot) or "Lock Hosts File" (Zone Alarm) before proceeding.

PDM Connection Workaround: If a DNS server cannot resolve the server name, technical support may advise manually adding the server IP and name to the local hosts file to bypass the lookup.

File Status: Ensure the file is not set to "Read-only" in its properties and does not have a .txt extension hidden by Windows. 2. Windows File Blocking (Blank Screen Error)

A common installation error is a "Blank Installation Manager" screen.

Cause: When installation media is downloaded as a ZIP, Windows Explorer may block specific HTML files during extraction for security.

Identification: This occurs primarily in the directory: \sldim\lang\english\HTML\. Resolution: Navigate to the \HTML\ folder.

Right-click on frameset.html (and others if necessary) and select Properties. Click the Unblock button at the bottom of the General tab. 3. Network & Firewall Restrictions

Outbound Rules: If SOLIDWORKS is unable to connect for activation, a new outbound rule may need to be created in the Windows Firewall to "Allow the connection" for the specific program executable.

3DEXPERIENCE Launcher: For modern cloud-connected versions, deleting the 3DEXPERIENCELauncher folder in C:\Programdata\DassaultSystemes\ and restarting can resolve stubborn installation hangs. 4. Summary Table of Resolutions Location/File Resolution Blank Install Screen \sldim\lang\english\HTML\frameset.html Right-click Properties -> Unblock Hosts Write Error C:\Windows\System32\drivers\etc\hosts Disable AV "Lock Hosts" setting; check Read-only status PDM Server Not Found C:\Windows\System32\drivers\etc\hosts Manually add [IP Address] [Server Name] Activation Blocked Windows Firewall Create Outbound Rule to "Allow connection"

Blocking SolidWorks Installation using Hosts File

The hosts file is a system file used to map hostnames to IP addresses. It can be used to block or redirect access to specific websites or servers. In this write-up, we will explore how to block the installation of SolidWorks by modifying the hosts file.

Why Block SolidWorks Installation?

There may be several reasons why you want to block the installation of SolidWorks on a computer:

Licensing restrictions: You may not have a valid license to use SolidWorks, and you want to prevent unauthorized installations.
Bandwidth conservation: SolidWorks installation files are large, and you may want to conserve bandwidth by preventing downloads.
Security: You may want to prevent the installation of software that could potentially compromise the security of your system.

Modifying the Hosts File

The hosts file is located in different directories depending on the operating system:

Windows: C:\Windows\System32\drivers\etc\hosts
macOS/Linux: /etc/hosts

To block the installation of SolidWorks, you need to add entries to the hosts file that redirect the SolidWorks installation servers to a non-existent or local IP address.

SolidWorks Installation Servers

The following servers are used during the SolidWorks installation process:

https://install.solidworks.com
https://www.solidworks.com
https://api.solidworks.com

Blocking SolidWorks Installation

Add the following lines to your hosts file:

127.0.0.1 install.solidworks.com
127.0.0.1 www.solidworks.com
127.0.0.1 api.solidworks.com

0.0.0.0 install.solidworks.com
0.0.0.0 www.solidworks.com
0.0.0.0 api.solidworks.com

Save the changes to the hosts file.

Testing the Block

To test if the SolidWorks installation is blocked, try to download and install SolidWorks. The installation process should fail or be redirected.

Reverting the Changes

If you want to allow the installation of SolidWorks, simply remove the entries you added to the hosts file.

Conclusion

Modifying the hosts file is a simple and effective way to block the installation of SolidWorks. This method can be used to control access to specific software or websites. However, it is essential to note that this method can be bypassed by using alternative installation methods or by modifying the hosts file itself.

Additional Considerations

Administrative privileges: Modifying the hosts file requires administrative privileges.
File permissions: Ensure that you have the necessary permissions to modify the hosts file.
System configuration: The hosts file is a system file, and modifying it may affect other system functions.

Best Practices

Document changes: Document any changes made to the hosts file.
Test thoroughly: Test the changes thoroughly to ensure they do not affect other system functions.
Revert changes: Revert any changes made to the hosts file when they are no longer needed.

If you're running into issues where a SOLIDWORKS installation is being blocked by host file entries—often due to leftovers from previous installations or network licensing conflicts—here is how to identify and clear those blocks. 🚩 Why this happens

SOLIDWORKS relies on specific host communication for license validation and installation data. If your Windows hosts file has entries pointing SOLIDWORKS-related domains to 127.0.0.1 or 0.0.0.0, the Installation Manager will fail to connect. 🛠 How to fix it (Host File Cleanup)

Open Notepad as Administrator: Search for Notepad in your Start menu, right-click it, and select Run as Administrator.

Open the Hosts file: Go to File > Open and navigate to:C:\Windows\System32\drivers\etc\(Change the file type dropdown from "Text Documents" to "All Files" to see the hosts file).

Identify Blocks: Look for any lines containing solidworks or related license servers (e.g., im.solidworks.com).

Remove or Comment: Delete those lines, or add a # at the start of the line to disable the block. Note: The exact domains change over time and

Save and Flush DNS: Save the file. Then, open Command Prompt and type ipconfig /flushdns to apply the changes immediately. 🛰 Network Licensing Tip

If you are using a SolidNetWork License (SNL), ensure your host file isn't accidentally blocking the server communication ports. The default ports are 25734 and 25735. If the installation still fails, you may need to add an exception for these in your Firewall settings rather than the hosts file. 🔄 What if it's still blocked? If the host file is clean but the install won't budge:

Repair the Installation: Go to Control Panel > Programs and Features, select SOLIDWORKS, and click Change > Repair your installation.

Check OS Compatibility: Ensure you aren't trying to install a version (like SOLIDWORKS 2026) on an unsupported OS like Windows 10, as support for that combination ended in late 2025.

Are you getting a specific error code (like 1603 or a connection timeout) during the installation? Windows 10: Block ANY Website by Editing The Hosts File

SOLIDWORKS installation failures or hangs, particularly during activation, can often be resolved by removing blocks for solidworks.com domains within the Windows "hosts" file [1]. Users should open Notepad as an administrator, locate the file at C:\Windows\System32\drivers\etc, remove lines referencing solidworks.com, and save the file to restore connectivity [1].

The phrase "SolidWorks host file block install" typically refers to two distinct technical scenarios: using the Windows hosts file to resolve server connection issues during a legitimate networked installation (such as PDM or SolidNetWork License Manager), or using it to prevent the software from "phoning home" to activation servers. 1. Using the Hosts File for Legitimate Installations

When installing SolidWorks in a professional environment, the client machine must often communicate with a license or PDM server. If your local network's DNS cannot resolve the server's name to its IP address, the installation or software launch may fail. How to Configure the Hosts File for Server Access:

Locate the File: Navigate to C:\Windows\System32\drivers\etc\.

Run as Administrator: You must open Notepad as an Administrator to save changes to this file.

Add Server Entries: Underneath any existing text, add a new line with the server's IP address, a tab or space, and then the server name (e.g., 192.168.1.100 MyPDMSever).

Refresh DNS: Open a Command Prompt and type ipconfig /flushdns to ensure Windows recognizes the manual override. 2. Blocking Connections via the Hosts File

Some users attempt to block SolidWorks from reaching its official activation or update servers by redirecting those domain names to an invalid IP address, such as 127.0.0.1 (localhost) or 0.0.0.0. This is sometimes used in unofficial installation guides to prevent the software from verifying license keys against Dassault Systèmes' databases.

Commonly Blocked Domains (Proceed with Caution):While specific "block lists" change, they often target domains like: im.solidworks.com im-ak.solidworks.com dl-ak.solidworks.com 3. Troubleshooting "Blocked" Installations

If your legitimate installation is being blocked, it may not be the hosts file at all. Common culprits include: CurrentWare How to Block Websites Using the Hosts File on Windows 10/11

Understanding and Resolving SOLIDWORKS Host File Block Install Issues

SOLIDWORKS, a leading 3D computer-aided design (CAD) software, is widely used by engineers, designers, and manufacturers across various industries. However, users often encounter installation issues, one of which is related to the host file blocking the installation process. In this article, we will explore the concept of a host file, its role in SOLIDWORKS installation, and provide step-by-step solutions to resolve the "SOLIDWORKS host file block install" issue.

What is a Host File?

A host file, also known as a hosts file, is a text file used by operating systems to map hostnames to IP addresses. It is a crucial component of the Domain Name System (DNS) that allows users to access websites and other network resources. The host file is usually located in the system directory of a computer, and its primary function is to override DNS queries and redirect them to a specific IP address.

The Role of Host File in SOLIDWORKS Installation

During the installation of SOLIDWORKS, the software requires access to specific servers to verify the license, activate the product, and download necessary files. The host file plays a vital role in this process by directing the installation wizard to the correct servers. However, if the host file is misconfigured or contains incorrect entries, it can block the installation process, resulting in a "SOLIDWORKS host file block install" error.

Causes of SOLIDWORKS Host File Block Install

Several factors can contribute to the host file blocking the SOLIDWORKS installation:

Incorrect or outdated host file entries: If the host file contains outdated or incorrect entries, it can prevent the installation wizard from accessing the necessary servers.
Malware or virus infections: Malware or viruses can modify the host file, causing issues with the installation process.
Network configuration problems: Network configuration issues, such as DNS resolution problems, can prevent the installation wizard from accessing the necessary servers.
Firewall or antivirus software interference: Firewall or antivirus software can block the installation process by intercepting the communication between the installation wizard and the SOLIDWORKS servers.

Solutions to Resolve SOLIDWORKS Host File Block Install

To resolve the "SOLIDWORKS host file block install" issue, follow these step-by-step solutions:

Solution 1: Check and Update the Host File

Open the host file in a text editor (e.g., Notepad) as an administrator.
Check for any entries related to SOLIDWORKS or Dassault Systèmes (the company behind SOLIDWORKS).
If you find any entries, comment them out by adding a "#" symbol at the beginning of each line.
Save the changes and close the text editor.

Solution 2: Reset the Host File to Default

Open the Command Prompt as an administrator.
Type the command netsh winsock reset and press Enter.
Restart your computer to apply the changes.

Solution 3: Disable Firewall and Antivirus Software

Temporarily disable your firewall and antivirus software.
Try installing SOLIDWORKS again.

Solution 4: Use the SOLIDWORKS Installation Manager

Download the SOLIDWORKS Installation Manager from the official Dassault Systèmes website.
Run the installation manager and follow the on-screen instructions.

Solution 5: Contact SOLIDWORKS Support

If none of the above solutions work, contact SOLIDWORKS support for further assistance. They can provide personalized guidance and help you resolve the issue.

Best Practices to Avoid Host File Issues

To avoid host file issues during SOLIDWORKS installation:

Regularly update your host file: Ensure your host file is up-to-date and free from incorrect entries.
Use a reliable antivirus software: Install and regularly update antivirus software to protect your system from malware and viruses.
Configure your network correctly: Ensure your network is properly configured, and DNS resolution is working correctly.
Disable firewall and antivirus software during installation: Temporarily disable firewall and antivirus software during the installation process.

In conclusion, the "SOLIDWORKS host file block install" issue can be resolved by understanding the role of the host file in the installation process and applying the solutions outlined above. By following best practices and taking proactive measures, you can avoid host file issues and ensure a smooth installation experience. If you're still experiencing issues, don't hesitate to contact SOLIDWORKS support for personalized assistance.

I understand you're looking for information about modifying the hosts file to block SolidWorks from contacting license servers — typically done to prevent online license validation after installation.

However, I must first clarify:

Circumventing legitimate license checks for commercial software like SolidWorks is a violation of its End User License Agreement (EULA).
It can also be considered software piracy if you don’t have a valid license.
If you are a legitimate user (e.g., with a standalone or network license), you shouldn’t need to block activation servers — proper licensing handles this legally.

That said, for legitimate cases like:

Stopping the software from “phoning home” for telemetry (privacy concerns)
Preventing update prompts in a controlled offline environment
Troubleshooting license manager conflicts

…you can block specific domains by editing the hosts file.

Step 6: Run the SolidWorks Installation Manager

Now proceed with the SolidWorks installation. The installer will attempt to connect to the blocked domains. Depending on the installer version, one of three things will happen:

Success (for offline use): The installer times out on each connection attempt and falls back to a manual or offline activation mode. You will need a valid activation code generated from another machine.
Failure (some versions): The installer throws an error like "Unable to connect to licensing server" and aborts. In this case, you may need to temporarily unblock one or two specific domains, complete the activation, then re-block.
Slow installation: Each blocked connection may take 20–30 seconds to time out, making the installation process significantly longer. Patience is required.

Phase 1: Locate and Prepare the Hosts File

Open File Explorer.
Navigate to: C:\Windows\System32\drivers\etc\
You will see a file named hosts (no extension). You might also see hosts.ics or lmhosts.sam—ignore those.
Backup: Right-click the hosts file, copy it, and paste it to your desktop. This is your backup.

When NOT to use the Block

Education Licenses: These require yearly online re-activation. Blocking will cause failure.
Term Licenses (Monthly/Yearly): Blocking will prevent renewal validation, causing the software to lock you out on day 31.
Cloud Services: If you use DraftSight Connected or 3DSwym, do not block.

What it is

The hosts file is a local OS file that maps hostnames to IP addresses before DNS is consulted. By mapping a SolidWorks activation or license-server hostname to 127.0.0.1 (or another unreachable IP), the system cannot reach that server and activation/license validation requests fail.
Typical targets include SolidWorks activation/serial-check domains or named license server hostnames.

Step 5: Test the Blocking (Optional but Recommended)

Before launching the SolidWorks installer, test that the domains resolve to 127.0.0.1:

ping activation.solidworks.com

You should see replies from 127.0.0.1 or a "General failure" message. If you see an external IP address, the hosts file is not being respected (check for typos or group policy overrides).