Problem with Windows Vista 32bit Premium edition, and nvidia

Quite a few months ago computer screen would go black, then return and tell me the display driver "nvlddmkm" failed but recovered. I didn't know much about it at all. Eventually my computer crashed without a blue screen, and every time after that when i turned it on the screen was broken in fragments and such. I sent it in to the manufacturer to get it fixed. Now, months later, it is still telling me the nvlddmkm is failing, and many times my computer will black out. I can still restart the computer. Also sometimes it will bluescreen now and tell me the video scheduler has encountered an error of some sort. A friend of mine has helped me change and upgrade display drivers a few times, but it still encounters the same errors. my computer is an hp pavilion dv9000 and the video card is an nvidia geforce go 7600.

Some days i can go along on my computer without a problem, and then sometimes it will crash like i have stated. Usually after it begins to crash that day, it will crash repeatedly if i try again soon. At first it only started when i was in some sort of gaming program, but eventually on the rare occasion it will crash at the desktop. If it helps, i can tell when it is about to crash because in the game, the screen will either try to break up into fragments, or what looks likes rays will seem to "shoot" out of the screen from the very middle.

That's all i can really tell i believe. Sorry it's kind of bunched, and if a thread was already mentioned about this i didn't see it =[

thanks