game lag after 5 minutes

hey guys i have a big problem: i have mw2 buyed from steam and for 2 weeks worked perfect but yesterday i got that big problem: after 5 minutes of game i have a game lag like if my pc doesnt support mw2 but it does......... this happens all the time how can i resolve? it's impossible to play!

PS: i dont use any hacks..

1. reinstall mw2
2. try it on a different computer
3. call steam support

Thats all I can think of. I hope you get it working again

If it runs fine for five minutes then it might be virus on your computer, or try lowering the graphics if nothing else works try reinstalling.

ok i'll try reinstalling even if took me a lot of time xD thanks

Most probably solved if he hasn't posted in the thread...