I too had the same prob, did the same thing ,now its goodI was crashing also when TG launched . Especially i would crash in dungeons. For me it was vertical sync , even tho i had it enabled all that time before and never caused a problem . So i disabled it from game and enabled it from nvidia control panel.If you haven't already delete shader cache and user settings and check if some of your graphics options are to blame.
Also in case you have nvidia drivers the last ones are problematic, so revert to earlier ones .