Once Windows boots to the desktop, check if Mastercam launches.
Leftover "UpperFilters" or "LowerFilters" in the Windows Registry can cause universal serial bus (USB) controllers to fail.
D. Repair Windows driver store and system files
A fresh installation often resolves the issue if the previous installation was corrupted. mastercam+x72022+virtual+usb+bus+error+39+fixed
If the registry fix doesn't work, try a full reset of your USB stack. Open ( devmgmt.msc ). Expand Universal Serial Bus controllers .
Corrupted driver registry keys frequently lock Error 39 into place. A clean wipe of the emulator is required. 1. Remove the Broken Device Right-click the Start Menu and select .
This is a deep hack. It works for Mastercam X7 (and similar older HASP-protected software) on Windows 10 22H2 and early Windows 11 builds. Not for production environments without rigorous testing. Once Windows boots to the desktop, check if
The quickest fix for Error 39 is turning off Windows Memory Integrity, which permits the OS to run the specialized dongle driver. Click , type Windows Security , and press Enter . Choose Device security from the left-side panel.
both values (right-click → Delete). Do not delete any other entries.
file as an administrator. When the Windows Security prompt appears, select Install this driver software anyway 4. Advanced Troubleshooting Tips Change USB Ports Repair Windows driver store and system files A
(critical for old X7 drivers)
Navigate exactly to the following directory pathway: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\36FC9E60-C465-11CF-8098-00AA004C324E
Error 39 is a Windows operating system error (CM_PROB_DRIVER_FAILED_LOAD). It occurs when:
Error 39 is a standard Windows Device Manager error code. When it occurs with a Mastercam virtual USB bus emulator, it usually means:
The "Error Code 39" in Mastercam (typically related to the Virtual USB MultiKey or HASP drivers) usually indicates that Windows cannot load the device driver because it is either corrupted, missing, or blocked by security features. This is a common issue on Windows 10 and 11 due to enhanced security protocols like Memory Integrity.