Very serious graphics problem

Not sure if this is hardware or software at this point.

I am running Windows 7 64-bit which I installed about 3 weeks ago. I have 2 geforce 8800 GTS cards. Everything was running fine until 3 days ago when I started getting regular crashes when doing anything graphics intensive. It kept getting worse and worse, till I could only boot to safe made. I reinstalled the latest drvers and that only made it worse.

Now, I can't boot windows at all, graphics driver just crashes. If I boot to safe mode I get this strange vertical lines on the screen. I am even getting those wierd lines over the BIOS bootup now (very scary).

I am going to try removing one graphics card and booting them one at a time.

ANY advice would be apreciated, thanks.

UPDATE: Bios and safe mode seem fine now, not seeing those wierd vertical lines. Using this opportunity to back-up everything before trying to boot Windows normaly. Still running both cards right now.

 

You could be seeing the demise of a PSU, what PSU is it?

If it was happening to me I would pull out the multimeter and see what the 12volt rail was doing.
you should see about 11.8volts(under load) or more, if it's dipping to far you will have problems.

 

I tried the cards separately and It seems that one works and one does not. Currently, it's running on that one card just fine, but it has only been on for a little while.

I went into the BIOS and it showed the 12 V reader fluctuating between 11.98 and 12.02. I'm too lazy to open up my card and I haven't seen my multimeter for over a year (time to buy a new one I guess). I don't think that it is the PSU anyway as it is relatively new, high-end, and has been running incredibly close to proper voltage on all fronts since I installed it. I'll be keeping an eye on it though.

So, how about some recommendations for good graphics cards that are under $300. Maybe I should start a new thread with this question.