The Sims Medieval through Steam

I was repeatedly told by EA support to post this issue in the forums, so here I am. The Sims Medieval will either crash immediately or run as a background process through Steam no matter what I do. I've tried running it in compatibility mode for Windows 7 and Windows XP v 3, I've tried using Powershell to run it through CPU 0 and CPU 1 only (it will not apply to TSM.exe no matter what I try), I've tried running everything as an administrator, I've tried a clean boot with zero programs running- nothing works. I've been told that the "concern team" will reply to me here, so please advise. I bought the game only ten years ago and wasn't expecting it to be completely inoperable by now, especially with all the troubleshooting I've done. I tried activating my CD key in Steam (again), in the EA launcher, and in the Sims 3 website, but I haven't had any luck with activating a "fresh" version of the game, if anyone's wondering.