If this is your system: http://h18002.www1.hp.com/products/quickspecs/11632_div/11632_div.HTML
then the answer is no. The motherboard is too old. Best route is to sell it intact and buy a used system with windows 7 already installed. I use craigslist alot; lots of bargain core2 duo systems, some with 7, for $150 or less.