If the machine is unaltered from factory you call it in. HP, Dell and others do not make perfect machines and some come with the BAD CAPS problem you can google. It's a shame to read posts where people didn't call it in and months later out of warranty they do. The call goes like this.
"It's been doing this since I got it."
"Sorry but our records show no trouble reported during the warranty."
"So you won't fix it (for free)?"
"The warranty is ..."
Call those things in.
My Vista HP 64-bit version has been freezing up every time I boot the last 24 hrs. It is a total and irrecoverable freeze, but I never see a BSOD. Also, I have run CheckDisk and the WD drive diagnostics on my Raptor and both came out clean. Am I right to assume that no BSOD here is likely that it is a software issue and not a hardware one? I say this from previous experience with a bad mobo in a previous computer (laptop) where it would throw BSOD's. But this is just freezing with whatever is going on on the screen.