HEY, I bought a HP PAVILION M9400F-E desktop pc from WALMART, it has-AMD LIVE SMARTER DIGITAL ENTERTAINMENT,AMD PHENOM X4 9750 QUAD-CORE 2.40GHZ W/ A 2MB L2 CACHE,2000MT/s system bus, and 8GB RAM, 750GB HARD DRIVE,supermulti dvd burner with light scribe technology, ATI RADEON HD 3650 videocard(which I want to replace with a better card to play highly graphic 2008-2009 pc games)I contacted HP who made the pc and they gave me the following info.-the card in the pc is a AMD RADEON HD3650 (SKYRAIDER), the motherboard on my pc has 1)one PCI EXPRESS X16 slot. the power supply specifications of my pc are-INPUT VOLTAGE, 100-127v/3A(50-60HZ) 200-240V/2A(50-60HZ). MAX. OUTPUT WATTAGE-350 WATT. So when I upgrade to a new/different card will I need to replace my power supply also? how difficult is that? is it something I can do myself? how expensive are power supplies? I want to get a card that will work good with my pc and at the same time is able to play all the best most demanding games to come in 2009, I would like to get the cheapest card that accomplishes all this, my funds are limited. so I need suggestions and advice.