Windows 7 64-bit
Cooler Master CM650 Nvidia Edition Case
Nvidia 750i Motherboard
Q9400 2.66ghz Quad Core processor running 50C idle 63C with heavy load
4 Gigs of Centon Ram
2x 1gb BFG 9800 GT's in SLi running 60C in Idle 70C with heavy load
650 watt SLi ready non-modular PSU (I want to say its a Corsair but I might be wrong)
2 LCD monitors (27" Westinhouse hooked up with DVI to HDMI on top graphics card) (18" Soyo hooked up with DVI to VGA on lower graphics card)
1tb System HDD and 2x 500gig HDD and a 2tb external hooked up through eSata
I recently installed the 197.45 Nvidia driver for Windows 7 64-bit (pretty sure this is the issue). It started freezing every 1-2 minutes for like 5 seconds and every 10 minutes or so the screen turns black for like 15 seconds then turns back on and a window pops up saying something like Nvidia Windows Mode Kernal Driver has stopped responding and has recovered, and it has to do with 197.45(I tried using the driver sweeper and installing the 185.85 driver but it did the same exact thing). I tried rolling back the nvidia driver and it seemed to have stopped the screen going black (actually it ended up happening again) but it still freezes frequently. I called BFG and they recommended a program called driver sweeper and to use the 185.85 driver. It still hangs. I even reformatted and reinstalled Windows 7 64-bit everything was working perfect until I got done installing everything from Skype to the 185.85 driver and it has started to hang again. I tried to finish watching a movie and the freezing was unbearable.
I have done a little research and it sounds like one of a few problems (ill try some of these when i get home):
1) Disabling integrated graphics in bios
2) To small of a power supply (im gonna run a power consumption calculator)
3) Check the System Event Log for any errors
4) Clean and reapply thermal paste on CPU (may have put a little to much on or might not have spread it well enough)
5) Add more case fans and maybe a new CPU fan/water (when I have more money)
Well sounds like purely a driver compatibility issue. I guess try getting the previous version drivers before 185 even. Maybe contact Nvidia about the issue.
It could be the PSU if it doesn't have enough amps, or it could be that the cards are idling too low for a 2nd monitor which you could change with a bios flash (voids warranty *technically*). If you install drivers and it happens again, see how it works with just 1 monitor for the time being. Or see if disabling SLI fixes it. Granted it's not a fix but it can help to figure out where the problem lies.