: Go to Windows Security > Device Security > Core Isolation details and turn off Memory Integrity .
3. Troubleshooting Common Errors (Code 39/Digital Signature)
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: Reboot your system. Open the Device Manager and look under "System Devices" or "Universal Serial Bus controllers" to confirm the Virtual USB Bus is listed without warning icons.
: Re-verify that Memory Integrity is toggled off in Windows Settings and run bcdedit /set testsigning on again in CMD. Virtual USB Bus Multi-Version Conflicts : Go to Windows Security > Device Security
Error 39 often occurs because the driver is not digitally signed in a way that Windows 10/11 recognizes.
Restart your computer. A "Test Mode" watermark will appear in the bottom-right corner of your desktop. 2. Turn Off Windows Defender and Antivirus Installing "Virtual USB Bus" drivers or emulation software
Select the virtual driver from the list (it may appear as Virtual USB MultiKey or Virtual USB Bus ). Click to start the installation.