Originally Posted by TheReaperWaits
Would you suggest I re-instal following that guide?
Yes, I would. Swconfig is reading your OS as Win9x, which means that the game was not installed, nor is it being run in XP SP2 compatibility mode, which is necessary for the game to run correctly. It's very likely that not running the game in XP SP2 compatibility mode resulted in a corrupted save.
Keep your saves and reinstall. If you still have the problem, try going back to an earlier save.