Can you please edit your first post to include your computer specs? Also, if your game is patched with the most current patch and you're using mods, make sure the mods are up to date. Quite often, patches make mods created for TS3 unusable.
Also when was the last time ytou took the side off your PC and cleaned it out with caned air? Or had the whole thing cleaned?? Could be it is over heated?