Screen Saver Disabled Registry Setting

OK so I couldn't change my screensaver as the dropdown had been disabled.

To fix this delete the registry keys under:

HKCU\software\policies\microsoft\windows\control panel\desktop

Then run
%SystemRoot%\System32\RUNDLL32.EXE user32.dll, UpdatePerUserSystemParameters
so dont need to reboot to make effective.

Now posted here I should never forget...