At a guess, judging on the screenshot, I would say your Graphics card is slowly dieing.
Try the games on the 'lowest' graphic settings ingame, see if the game plays for longer before freezing up (crashing).
Then try the 'highest' graphic settings ingame and see if it crashes any faster.
If the card 'is' dieing it will most likely crash straight away after applying the Highest graphic settings.
Do you have another graphics card you can use as a test, maybe borrow one from a friend to test?