Technically speaking i guess...
Video cards USUALLY refer to an actual card that is physically independant from your motherboard. I didn't realize you were speaking about your onboard video because you said it was NVDA, and all the reviews i read i didn't see that in there (my fault).
This creates a larger issue, because although you can purchase a separate card for video and plug it into your AGP/PCI slot, the issue is that since your onboard video is failing, the rest of the board COULD follow shortly.
Two options here, one you could purchase a new standard video card for around 60 bucks (assuming you don't need anything fancy) and use that, realizing that it MAY not fix the issue (considering A we don't know for sure if it is just the video card crashing, and B the entire board could be failing).
Second option is to replace the board, which in that case you might as well purchase a new system since yours is an older one (you'd end up having to purchase a new power supply, board, ram, video, processor).