I play League of Legends and Dota 2, and the games would freeze and quit responding, I tried to update my drivers for my Geforce GTX 660 but the games would continue to crash. Sometimes the games crash like 6 times in 15 minutes and on a minimum like once every 10th minute.
If this is happening in all games then it could be a hardware or DX issue or temp over heating issue. But if those 2 games than you know why.
Those games are causing problem with the 660 driver as NVidia always optimize its drivers for recent and popular games. You can try running those in window mode or windows xp compatibility mode by right clicking on their icon on desktop than select properties.