I'd start by going the splash window for each game (TANE, TRS19, and TRS22 -- the earlier games don't have that option) and click on the "Install" tab. This will show you where you've set the game to put all your content. If one of them is on your C:\users\...... drive, then that's the one storing all those files and making your C drive sluggish. If you find it, there are instructions for moving the folder to another drive.
From your first photo, it would appear that TRS19 is the culprit.
Bill