Hello there, sorry for necromancing this thread, but I had the exact same problem and was able to fix it (yay!)... so I wanted to post a reply in case anyone else is browsing for the same answer. I'm sure the OP has moved on, but this might help others.
The window stretching has to do with that 'SciTech Display Doctor' tab added to the Display Properties (desk.cpl) GUI. I honestly don't know what misalignment of stars made it act the way it did for myself and the OP, but for me it was bogus anyway since it would just disappear when I clicked on it. And, yes, there's still a way to apply changes or just keep tabbing off all the active options and hit 'enter' when you're sure you've landed on the OK button, buuut... this is better:
Run > regedit
Navigate to this folder: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Controls Folder\Display\shellex\PropertySheetHandlers
You'll notice there's a subfolder for SciTech here. I played it safe and just renamed the "PropertySheetHandlers" folder to "PropertySheetHandlersX" to disable this entry, though it might be safe to delete it entirely.
NOTE: I also cleared the Display Properties cache, but I did this before the above, and that in itself didn't work. In case there was a magic combo of things, that can be found here:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Controls Folder
There will be an entry labeled "Presentation Cache"... I just deleted it (after exporting it in case I tanked everything).
I'm not necessarily THIS savvy where something so deep in the weeds of technology is concerned. This was more like a combination of piecing together info from around the internet, and dumb luck, so just paying it forward. :D
