Ok..
I'm using windows XP pro service pack 1. I got a P4 2.66, 512 mb ddr, ati radeon 9000. The games i am trying to play is DeltaForce Blackhawk down, Battlefield 1942 and Vietcong. I can run a game in 5 min then it get stuck and sometimes it shoutdowns the computer! All these games runs perfect when i dont have plugged in the ac adapter.