Re: [SOLVED] Moved my Sims 4 files to a new drive, game data gone?
@ragingredfox If you'd like to be able to store your Sims 4 user files on D, you have two options. One is to move the entire Documents directory to D, which is simple and supported by Windows.
https://www.tenforums.com/tutorials/74952-move-location-documents-folder-windows-10-a.html
The other is to create a symbolic link that points to your Sims 4 folder on D, so the game knows where to find your files. If you use this method, please make sure to get the command exactly right, and back up your saves beforehand just in case something goes wrong the first time you try.