Q: Why does my machine show a Test Mode stamp in the bottom right corner of my desktop?

A. If your system shows a "Test Mode" stamp in the bottom right corner of your display you have likely turned on test signing of drivers.

This can be confirmed with the bcdedit /enum command (note the testsigning value):

  1. C:\Windows\system32>bcdedit /enum
  1. Windows Boot Manager
  2. --------------------
  3. identifier {bootmgr}
  4. device partition=\Device\HarddiskVolume7
  5. description Windows Boot Manager
  6. locale en-US
  7. inherit {globalsettings}
  8. bootshutdowndisabled Yes
  9. default {current}
  10. resumeobject {5f599037-de4a-11e1-8931-b2ebfcc6f15f}
  11. displayorder {current}
  12. toolsdisplayorder {memdiag}
  13. timeout 30
  14. Windows Boot Loader
  15. -------------------
  16. identifier {current}
  17. device partition=C:
  18. path \Windows\system32\winload.exe
  19. locale en-US
  20. inherit {bootloadersettings}
  21. recoverysequence {5f59903b-de4a-11e1-8931-b2ebfcc6f15f}
  22. recoveryenabled Yes
  23. testsigning Yes
  24. allowedinmemorysettings 0x15000075
  25. osdevice partition=C:
  26. systemroot \Windows
  27. resumeobject {5f599037-de4a-11e1-8931-b2ebfcc6f15f}
  28. nx OptOut

To fix the problem turn off the test signing and enable the integrity checks:

  1. C:\Windows\system32>bcdedit.exe -set loadoptions ENABLE_INTEGRITY_CHECKS
  2. The operation completed successfully.
  3. C:\Windows\system32>bcdedit.exe -set TESTSIGNING OFF
  4. The operation completed successfully.