Hi there, my friend wants me to install a video card in his HP SR5710Y. So I was looking at the specs of his system and he needs another power supply because his is a 250w...anywaiz the problem is that wherever i look for the case type like atx or w/e it says tower and i have no idea what this means it isnt too specific. So if anybody can tell me which power supply type would work with his case it'll be a huge help thx.