I recently reinstalled windows 7 and now i get a CTD every time i try to load any of my old save files. Starting a new campaign works just fine, but the old saves just won't work.

I realized that the problem may be due to an incompatible version, because I can't remember exactly which version i had installed previously. I've tried loading with "vanilla" RTRVII, hotfix1 and with patch1a. None of these made any difference, I still get a CTD on the loading screen.

Was there a "temporary" version of some patch that has now "disappeared"?
I doubt that I had patch1a installed, because the "hints" on the loading screen were there when I played (in patch 1a it just says something like "RTR Patch" every time).

Did I run some obscure version of the game or might there be some other reason the old saves wont work?

The OS I reinstalled is Windows 7 Ultimate 64-bit (the exact same version i previously used without issues)