How Do Drivers Break

I haven't run into before which is confusing, 3 weeks ago I installed a new graphics card, and clean installed the drivers, last night I was playing Grand theft auto 4 and my computer froze, after I reset the computer it froze again instantly when I loaded it. so I gave up for the night, the next day I tried again and it ran for 5 mins and started freezing, so I reset when I came back to windows the mouse wasn't moving around the screen properly so I guided with the keyboard, after which the display adapter stopped responding twice and eventually froze. so I reset went to safe mode, checked for viruses, malware, all the programs turned up nothing I cleaned my registry had like 3 or for errors, and reinstalled my nvidia drivers and reset, now it works again. I mean I know how to fix crap when it screws up but how did the driver break in the first place, I didn't install any software, or updates or anything since I installed the new graphics card, I've been playing starcraft 2 and GTA4 on and off but that's it so I don't get how a driver can just decide to kill itself, anyone know? I checked the temperature and it was at 25 while Idle which I assume is good for a graphics card from what I've seen. I've run memory diagnostics and nothing either, so I don't get it