I'm not sure if this is the right section, feel free to move it if you want.
I'm having a little trouble with the performance of my PC. Running windows and small applications is fine, but when playing games, what tends to happen is they will run fine at first, but then become laggy and slow, up to a certain point when all of a sudden it all goes back to normal again, running perfectly smooth. Then the whole process wil start again, go slow, then be fine again. This has happened with games like GTA: Vice City and Counterstrike. It's only a minor problem, but after a while it's annoying, so if anyone has any ideas what's wrong, then I'd be very grateful.