I have a HP Pavilion A300N, running windows XP. I recently purchased a ATI Radeon 9200 Graphics card. I installed it and have the screen set at 1024 x 724. I cleaned the registry and have reinstalled the card. However, whenever I am playing a game, the computer will lock up and I have to shut it down. the computer hs a 240 watt power supply and is about a year old. Any suggestions or tips will be appricaiatec. Thank You