This should also work on Windows 7, 8, 8.1, and Windows 10.
There’s a quick way you can enable or disable this annoying window from the command line:
Disable UAC
C:\Windows\System32\cmd.exe /k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f
Enable UAC
C:\Windows\System32\cmd.exe /k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 1 /f
After you enable or disable UAC, you will have to reboot your computer for the changes to take effect.