Windows 11 allows only digitally signed device drivers to be loaded at startup. If the device driver is not digitally signed, then it will not be loaded and the file belonging to the driver will also get removed. This is because of the protection layer built into Windows 11.
But what if you are a developer and want to test your latest device driver which is not yet digitally signed? In that case, you can enable the test signing mode on Windows 11. Once the test signing mode has been enabled, you will see “Test Mode” watermark near the lower-right corner of your screen. This “Test Mode” watermark cannot be removed unless you disable the Windows 11 test mode.
Here is how you can enable the Windows 11 test mode:
- Right-click on the desktop and select Open in Windows Terminal. This will open Windows Terminal. Alternatively, you can also use Windows PowerShell or Windows Command Prompt (cmd.exe).
- Type in the following command: bcdedit -set TestSigning On
- Restart Windows PC. When Windows has restarted, you will have test signing mode enabled.
You can verify that Windows 11 test mode has been enabled by looking at the Windows desktop watermark. You should be able to see “Test Mode” near the notification area of the Windows desktop.
Similarly, you can follow these steps to disable the Windows test signing mode:
- Launch cmd.exe shell, Windows Terminal or PowerShell.
- Give the following command: bcdedit -set TestSigning Off
- Restart your Windows PC.
You should never keep test signing mode enabled for long periods of time. This allows loading of the unsigned drivers at Windows boot. This means that some malicious device drivers can also be loaded if the test signing mode is disabled. Windows skips performing security check at the boot time when this mode has been enabled. You can use this mode only temporarily for testing some drivers.