Mastercam Virtual Usb Multikey Not Working May 2026

For IT administrators or frequent sufferers, this batch script resets the Multikey in one click.

Save as reset_multikey.bat and Run as Administrator:

@echo off
echo Stopping and removing old Multikey...
net stop multikey
sc delete multikey

echo Removing driver from System32... del /f /q C:\Windows\System32\drivers\multikey.sys

echo Reinstalling driver... copy "%~dp0multikey.sys" C:\Windows\System32\drivers\multikey.sys

echo Creating and starting service... sc create multikey type=kernel start=auto binPath=C:\Windows\System32\drivers\multikey.sys sc start multikey mastercam virtual usb multikey not working

echo Disabling signature enforcement... bcdedit /set testsigning on

echo Restarting Device Manager refresh... pnputil /scan-devices

echo Done. Reboot now? (Y/N) pause


You’ve just installed Mastercam. You’re ready to machine complex parts, but when you launch the software, it freezes, crashes, or greets you with a dreaded "Hasp not found" error.

You check your Device Manager, and there it is—a yellow exclamation mark hovering over the Virtual USB Multikey. Or worse, it’s listed under "Other Devices," floating in digital purgatory.

This is a common headache for CAD/CAM administrators and users. It’s a clash between modern operating systems and legacy driver architecture. Here is the breakdown of why this happens and how to exorcise the ghost.

Provide the following when opening a ticket: For IT administrators or frequent sufferers, this batch


If the Multikey worked yesterday but failed after an automatic update:

Note: This is a temporary workaround. Future updates will re-introduce the block.


If the driver is unsigned, you must tell Windows to relax its security standards temporarily.

  • Update the Driver Manually:

  • If the virtual dongle uses a local license file, confirm the file is present and not blocked by Windows (right-click → Properties → Unblock if present).
  • Temporarily disable antivirus/firewall (or add exceptions for Mastercam and Sentinel/Hasp services) and retest.
  • Run Mastercam as Administrator.