So thinking of building a budget gaming PC reusing a few parts from this one i Built. Currently gonna thinking ill reuse the HD wich is 300gigs, the case and http://www.newegg.com/Product/Product.aspx?Item=N82E168... which is about 4 years old. my question is will that Power supply be fine for current video card setups? If i have to i will get a new psu but if that will be fine, i will reuse it. I only have around 700-800 bucks to spend. Also im using windows vista, Should i upgrade to windows 7 for gaming.