Q: power source fan runs, hp pavillion,1.0 memory,2.50gb hard drive. xp media center edition.
A: most obvious conclusion would be that something overheated. if it comes back on I would download pcwizard2008 and carefully watch the temps. Have the wizard running while you play. Have it on the temperature and voltage screen. make sure you change the options to real time monitoring and change it to Fahrenheit instead of Celsius. In the middle of the game maybe after 3 or 4 minutes of playing do a ctrl+alt+delete and close the task manager but notice your temps (cpu&gpu) immediately. If possible make the game run in a window so you can watch it in real time.