All applications using WPF (Windows Presentation Foundation) suddenly show distorted window content and it won't refresh. Whenever the mouse pointer moves into or over such a window, the content (text, pictures, buttons, checkboxes) become distorted, blurred and/or simply are vanishing completely.

NahimicOSD.dll is causing the problem. It inhibits the orderly rendering of WPF applications. Therefore this seems to be a Dell/Alienware specific problem.

Workarounds:

Locate the nahimic blacklist (BlackApps.dat - path example below)...

C:\ProgramData\A-Volute\DellInc.AlienwareSoundCenter\Modules\ScheduledModules\Configurator\BlackApps.dat

and insert the name(s) (xyz.exe) of your affected application(s) into that list to avoid further affection by nahimic for this program(s). It's just a textfile - open, edit and save it with the texteditor (run texteditor as administrator).

In my case these applications are divelog.exe, NUP.exe (norton utilities)

The alternative solution is to switch off hardware acceleration for all WPF applications completely (in the registry):

[HKEY_CURRENT_USER\Software\Microsoft\Avalon.Graphics]
"DisableHWAcceleration"=dword:00000001

By default, hardware acceleration is enabled for WPF applications.

The disable hardware acceleration option is a DWORD value that is either 0 or 1. A value of 1 disables hardware acceleration. A value of 0 or the (by default) missing "DisableHWAcceleration" key enables hardware acceleration.

Just to share that with you as it took a while to find out the cause.