Yeah, I uninstalled the games, deleted their directories, then I reinstalled them all, and still no go. Then I backed up my documents and whatnot, formatted the drive, and did a clean install of XP MCE 2005. Installed the games, and they still don't work.
All of my other games work just fine, no problems at all. But The Sims 2, and its expansions, will give me absolutely no love. I am mystified by this problem.