Dissociative

I honestly have no idea how to find out any of those

Hey, I've been wanting to upgrade my old computer a bit, then give it to my son to use as a gaming computer (he's 10, so it obviously doesn't have to be the best) I want to upgrade the ancient Intel 82845g to a nvidia 6400 or so, would this be doable? It has a intel 4 2.8ghz processor/1066 ram thank you very much for your time