so my friend is thinking about buying this PC http://www.bestbuy.com/site/desktop-8gb-memory-500gb-hard-drive/1494198.p?id=1219052700181&skuId=1494198&st=ibuypower&cp=1&lp=2 only problem is he wants to upgrade the graphics card and it doesnt show the power supply watts any way of finding this out im hoping its at least a 450W... thanks for your help in advanced