Editing the Windows hosts file to block SolidWorks domains is a time-tested, lightweight approach to prevent the software from contacting external servers during or after installation. While it is not foolproof against modern anti-tamper measures, it serves as an excellent first line of defense for users who require complete offline control over their SolidWorks environment. Always ensure you are in compliance with licensing terms, and remember that the hosts file is a tool for legitimate network management—not a method for software piracy.
Proceed with caution, backup your original file, and test thoroughly before deploying to production machines.
The Windows hosts file (located at C:\Windows\System32\drivers\etc\hosts
) can cause significant blocks during SOLIDWORKS installation and licensing if it is restricted by security software or misconfigured. This typically occurs when the installer (especially for 3DEXPERIENCE Network Licenses
) cannot verify server connections or write necessary address redirects. 1. Primary Reasons for Installation Blocks Security Software Interference : Antivirus and firewall programs (such as SentinelOne
) often "lock" the hosts file to prevent malware from redirecting web traffic. If the SOLIDWORKS installer attempts to modify this file to resolve local server addresses and is denied, the installation will fail. Read-Only Attributes
: If the hosts file is manually set to "Read-only" in its file properties, the installer will be unable to update the necessary DNS mappings. File Mismanagement : If the file was accidentally renamed to
, the system will not recognize it as the active configuration file. Permissions Denied
: Modern Windows versions require administrative privileges to modify files in the directory. SOLIDWORKS Forums 2. Common Symptoms "Permission Denied" Error : Explicit error messages stating C:\Windows\system32\drivers\etc\hosts permission denied during the 3DEXPERIENCE Launcher setup. Blank Installation Manager
: While often caused by blocked HTML files from a zip extraction, a blank screen can also indicate the installer is stuck waiting for a connection that the hosts file is blocking. Connection Timeouts
: The Installation Manager may hang at a loading bar if it cannot reach the activation or PDM servers due to a DNS resolution failure that a manual hosts entry would otherwise fix. SOLIDWORKS Forums 3. Resolution and Manual Configuration
To resolve these blocks, you must often manually configure the hosts file to bypass failing DNS lookups: solidworks host file block install
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.
🛠️ 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). Editing the Windows hosts file to block SolidWorks
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
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.
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].
If you are looking for the specific entries to add to your Windows hosts file to prevent SOLIDWORKS from communicating with license validation servers during an installation or startup, you typically use the following lines. Hosts File Entries
To block these connections, copy and paste the following text into your hosts file:
127.0.0.1 im.solidworks.com 127.0.0.1 ext-im.solidworks.com 127.0.0.1 activate.solidworks.com 127.0.0.1 ext-activate.solidworks.com 127.0.0.1 standard.solidworks.com Use code with caution. Copied to clipboard How to Edit the File Open Notepad as Administrator
: Search for "Notepad" in the Start menu, right-click it, and select Run as Administrator Navigate to the Folder File > Open and paste this path: C:\Windows\System32\drivers\etc
Note: Change the file type filter in the bottom right from "Text Documents ( .txt)" to "All Files ( )" to see the file.* Open 'hosts' : Select the file named (it has no extension). Add the Text
: Scroll to the bottom, paste the entries above on new lines, and save the file. Rackspace Technology The Digital Drawbridge: On Blocking SolidWorks via the
Blocking these hosts is often done to bypass "Checking for Updates" delays or for troubleshooting license manager connectivity in private networks. If you are experiencing an "Installation failed" error, you may also need to repair the installation through the Windows Control Panel. Are you trying to resolve a specific error code during the installation process?
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:
That said, for legitimate cases like:
…you can block specific domains by editing the hosts file.
You cannot edit this file with Notepad normally due to Windows security.
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
Some SolidWorks network licenses rely on a "Heartbeat." If the software cannot ping the activation server every 30 to 90 days, it assumes the license is stolen and disables itself. Adding a block stops this remote kill-switch.
Cause: You didn't run Notepad as administrator. Fix: Close Notepad. Re-open via Right-Click > Run as Admin. Repeat the process.
You might have a valid license key, yet the installation fails. Here is why admins use the host file block during installation:
Malware often modifies the hosts file to redirect your bank to a fake site. If your antivirus sees a modified hosts file, it may flag it as Generic.Malware.Suspicious. You need to add an exception to your AV for C:\Windows\System32\drivers\etc\hosts.