

@mezpet99 I heard that AC Valhalla just needs to be on the same drive that Ubisoft/Uplay is installed on, which doesn't necessarily have to be the main OS drive.
So mine is:
C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher\games\Assassin's Creed Valhalla
You could try installing Ubisoft Game Launcher on your D drive, then moving your existing 'Assassin's Creed Valhalla' folder from wherever it currently is on your D drive, to the newly-created 'games' folder within the new Ubisoft folder on your D drive, that might work.