Problems with PC games crashing, and shutting PC down

[ajpattison]

Another of my occasional requests for help from people who know far more than me about such things...

I recently started playing a new game on my PC. it all ran fine, looked great,but after about 20 mins playing time, the game would crash, and then my PC would switch off completely. i have tried updating all drivers and running the game on the lowest possible settings, but it still kept happening. I shrugged and assumed it was some incompatibiity issue and put it down to experience.

Then today I had a go on an older game I hadn't played for a while. I had never had any problems with this before, or indeed any other game, and....(guess what's coming)... the same thing happened

Anyone got any ideas what's going on, or more to the point, how to set it right?

[SlackAlice]

Typical signs of overheating or grahics card drivers from the limited amount of information you've given.
What's your pc's specs and O/S. Also, what games were you playing. Are you getting BSOD?