Ok, I have had this problem in the past, but it stopped for awhile, but now its back. It usually just happens when I'm using Windows, not during games or anything. I'll be surfing, browsing through my hard drive, something on the desktop, and my mouse freezes up, and the keyboard locks. Then the monitor goes black, and tells me it's not recieving an input image. I have checked all my connections and they are all the way in, and the weirdest thing is, is that sometimes when it goes black, it goes that way for a few seconds, then comes back to the screen I was at. When its at the black screen, my computer sounds like its still running though. I've checked to make sure I have the latest graphics drivers, and I do. I have an MSI NX6600 GT if thats any help. Anyone else have any idea what this is? Thanks in advance.
Perhaps your 6600 Gt is not getting enough juice. How powerfull is the Power Supply in your computer? What is its wattage?
I doubt it is heat, but it is possible.
I believe its a 350w, possibly a 300. I have never messed with power supplies cause theres lots of complicated stuff about them that I don't know, and I don't wanna get something thats gonna mess my computer up.
That would be your problem, it is probably a cheapo, that can't even put out a steady 350 watts. Most power supplies are rated by the highest they can output, even if it only puts out that much for a single minute. So they Max Out at 350 watts, they don't run at 350 watts. So your Computer is very underpowered.
I would recommend getting a 400 watt power supply. These newer Video cards require a lot of power. You should be able to find a quality repair shop, that can replace your power supply for you. Although, it is not that difficult to do yourself. Just get an ATX-Pentium 4 power supply. P4 Power supplies should work with AMD motherboards. You will just have an extra cable hanging down.
In the mean time, you can increase the stability by downclocking your processor, and RAM. Then unplug any unneeded USB devices, or Drives. The less running the better, and the faster a processors, and video card run, the more power they need.