Bizarre freeze up issues on XP

Hey, this is my first forum post but i regularly browse the forums looking for advice or suggestions.

Recently however I've been coming across this strange problem resulting in my PC freezing up. Ive tried looking the problem up but no where have i found anyone with the same problem, I figured if anyone would know it would be you guys here.

My problem is that ill be just generally using my PC and it freezes and presents no messages, just things like mouse wont move and audio repeats. If im browsing the internet however it will stop loading pages about 30 or so before the whole PC freezes.

This tends to occur just after ive installed a new program because ive previously restored the system to a previous date and everything is fine. However during installing things I dont cut and corners and do everything as specified.

Im completely bamboozled with it now, I dont want to have to restore everytime it messes up.

Any suggestions?