I've been dealing with random crashes and spontaneous reboots for a couple months.  It mostly crashed during COD (graphics intensive) but crashed rarely for Demigod (CPU intensive) and L4D2.  I was originally hoping it was a driver issue since i uninstalled the asus AI drivers due to crashing issues and running win7 RC.   It turned out it wasnt after a windows ultimate install.  I thought it could be a ram issue next so i ran memtest and prime95 without errors.  THen due to the nature of which games actually crashed i thought it was a video card problem next.  It turned out not to be so I replaced the power supply this evening and haven't had a crash yet. 

Set your bios to defaults then adjust memory timings, boot order etc. Ie. don't overclock.

So, based on your problem I would look at the ram and run memtest overnight see if you get errors, if not then try prime95.  Another good computer stressor is OCCT (just google it). Run through those. 

Keep in mind that your ram can pass all of the tests and still have issues.

Once your ram has been tested and cleared I would look at your power supply, see if you can swap it out with another.  If the crashes still continue do a Bios update, then try swapping your vid card.

PM me with any questions.  Good luck!

j

It's most likely the video card, the GTX 280 and 8800 series of nvidia cards are slightly buggy, you will get a blue screen and the error will be in the nv_disp (I can't remember the spelling) driver.  Turn down the graphics options and it should make it go away, usually the driver/card crashes under heavy load because of heat, IMHO try to see what the heat on your graphics card is and maybe down clock it a bit if you know how to do that.

I have been getting some blue screens too lately, and I did some research because I suspected the Nividia graphics drivers. Turns out I was right.

More than 50% of users getting blue screens in games, have a defect driver. Either Nvidia has released a bad driver, (many people claim that), or simply the previous  uninstallation of the old driver wasnt done properly.

To test this, I did a proper uninstallation of the driver, and reinstalled it. There are certain programs, that are specifically meant to uninstall drivers. Not all drivers, but the most commonly used, like Nvidia, Ati, and Creative.

Anyway, I guess time will tell, because I didnt always get blue screens in demigod. Sometimes I would play 3 hours straight, and nothing would happen. And sometimes I would play 15-20 minutes, and then I would get the error.

@Widow_Maker: Configure your pc to NOT restart automatically when it gets a blue screen. That way, you can see what the problem is. I did it, and saw that it was a driver .dll file that was failing. This is Nvidia's driver problem, not hardware. That is, IF you have the same problem as me.

Edit: Do you ALWAYS get blue screens when playing Demigod?

Thanks for all the info guys, aye I always seem to get blue screens when playing. I think u are all right about the drivers as it has previously run fine. I guess I will just have to wait till Nvidia release a more stable driver.

I'm sorry jongalt but you are wrong here. An overheated videao card, doesnt result in a Blue Screen. Worst case scenario, is to see some artifacts and heavy gfx gliches, but thats it. Now in case that your card gets overheated so much that its way over the limit, then the pc will "hang" (frozen screen), and maybe some looping sounds etc. But not blue screen. This is not a hardware issue.

Besides, I already have Evga Precision installed, (I have an Evga card, so it came with it, in the box), and the fan is set at high rpm%.

My advice to Widow is: Check out the blue screen, to see which file is the problem. If it is a Nvidia driver file, then its the driver. But it could be something else too.

Anyway, there is only 1 sure thing:

It is a driver problem, at least for me.

p.s. since uninstalling and installing the driver properly, I havent had an error in 3 days. still not sure if it is fixed though.

Report: Still no blue screens, even though I have played not only Demigod, but also run some heavy Stability tests for the Gfx card. Note that, I overclocked my card for these tests, to the maximum possible, in order to stress it as much as I can.

Still, the problem might appear when I least expect it. I am still not sure if it is fixed.

Update report: After about 30 games, I had seen no blue screens at all. Today i wanted to watch a replay. 4 minutes watching the replay, and I got a blue screen. Restart tried again. I used 10x speed, to skip to 4 minutes mark, so that I resume where i left it. Same thing. Blue screen. Tried 3rd time, Blue screen. All blue screens are within 5 minutes of watching the replay, and everytime it is the same file: nv4_disp.dll

For some reason, it is hyper sensitive to replays.

Since I found a way to reproduce the blue screen, I will try reverting to an older driver, since this is clearly the problem. And since Nvidia doesnt bother to release a new driver, I have no other choice. If this doesnt work, I will revert to an even older one, if this doesnt work either, then...I am stuck with it.

Oh well, at least it happens only on replays...

I have a gtx 260 myself, and i had the 195.62 drivers.

Since reverting to the 191.07, I get no blue screens, everything seems fine.

I hope the problems are gone now.