Windows 10/11 strict security policies.
A standard reinstall often fails because it leaves behind corrupted files.
"Error 39 on HASP virtual bus? Force legacy USB view. Use devcon to remove the bus, then manually assign a lower filter driver."
There are two main methods to resolve this, depending on your Windows version (Windows 7 vs. Windows 10/11).
Download the latest from Thales Group. Extract the files to your C:\ drive. Open Command Prompt as Administrator . Navigate to the folder using cd C:\path_to_folder . Run the removal command: haspdinst.exe -purge Run the installation command: haspdinst.exe -i Step 5: Update the Virtual USB Bus Driver Manually Force Windows to look directly at the correct driver files. mastercam+x72022+virtual+usb+bus+error+39+fixed
(critical for old X7 drivers)
The "Code 39" error for the Mastercam Virtual USB Bus (often associated with
Most likely, an anti-virus or security software is quarantining or deleting the driver files (like mcamvusb.sys ). You should add the Mastercam installation folder and the driver folder to the exclusion list (whitelist) of your security software to prevent this.
Follow these solutions in order, from the most common software conflicts to deep system configuration changes. 1. Disable Windows Core Isolation (Memory Integrity) Windows 10/11 strict security policies
If Method 1 did not work, the driver is likely being blocked by Windows because it lacks a valid digital signature (common with older emulator drivers).
The error often presents with the message: "Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)" or "Windows cannot verify the digital signature for this file. The signing certificate for this file has been revoked." This typically happens because the drivers used for Mastercam's virtual USB emulator are not digitally signed by Microsoft, or their signature has been revoked by Windows security updates. Recent Windows updates (like KB5004237) have tightened security policies, often leading to this exact issue.
These older iterations were built primarily for Windows 7 and early builds of Windows 10. They rely heavily on outdated sentinel environments. Running these versions on modern Windows 11 environments requires Core Isolation to be completely disabled.
Windows 10 and 11 block drivers that aren't verified by Microsoft. Force legacy USB view
You are trying to run Mastercam X7 (or a similar version) on Windows, but the software fails to launch or cannot find the SIM (license), displaying "Virtual USB Bus Error 39" .
C. Remove corrupted drivers and reinstall
Navigate to > Advanced options > Startup Settings > Restart . Press 7 or F7 to "Disable driver signature enforcement." Registry UpperFilters/LowerFilters Removal :