Crashing Drivers :(

Ok so I cant install anything newer than the latest nvidia "game ready" driver without crashing any game after 10 secs and even with that driver I cant install geforce experience without experiencing crashes. With newer drivers I can play like 10-60 secs and then the game crashes and it says that "nvidia driver has stopped working and succesfully recovered". I have had so much troubles with Windows 8 before that I think it might be the reason. So if reinstalling Win 8 is the only option, is there some kind of way to keep my games installed on steam so I dont need to download them again? 

My PC specs: i7 4770k, Asus GTX 780, 8 gigs of 1600mhz ram, 2×1tb hdd + 60 gb boot ssd, Asus z87 A

Things that I have tried:

Not installing those nvidia 3d driver things

Setting "prefer maximum performance" in nvidia control panel

Putting stock clocks to the gpu

Doing clean installation to driver 

 

Whats you PSU like. My friend had the same issue and it was his PSU being monstrously underpowered. Not saying yours is just an option it is the only part you did not list.

It is the fractal design 750w psu. More than enough for my rig :D

I still have the same problem after reinstalling win 8.1. Can actually anybody help me?