random restarts - sometimes won't even boot.

[wez130]

I've been having problems for a while now, both on XP and now on vista, computer restarts randomly, then goes to 'vista cannot start because some file is missing can't remember exact one, i was busy kicking crap out of pc at the time , but it was a system file. then i can leave it off 5 minutes and everything is fine and dandy again, till next time. Now, this used to happen also on XP, and since it's been happening, i've swapped out everything in my tower except the motherboard (Asus A8N SLI Premium) and the GFX (geforce 7600GT),i've had new memory, processor, hard drive and i have a decent PSU (thermaltake 550w i think)
I've not overclocked on this board or the processor so basically, i'm at a loss

any ideas?

 

[wez130]

If you have swapped everyhting except the mobo, then as Sherlock Holmes would say "after you have eliminated all options but one, then however unlikely, that one must be the solution" - change the mobo !

yeah, i obviously thought about that, but at the same time, how can the mobo be responsible?

It's an Asus so is still covered by the 3 year warranty. Do i just say that in an RMA, that i've eliminated every other option?