This is going to be bland im afraid but maybe someone has had the same problem. When the situation occurs this is what happens: the computer COMPLETELY locks up within half a second, itunes stutters to a stop, the mouse judders to a halt and the only thing that can be done is to swith the thing off at the mains.
This can happen at anytime, sometimes it happens on the XP screen as the computer is loading up (usually this is after a previous crash), on the Chldsk utility that runs or just as i login or just during normal running of the computer, ie its not like im using any memory hungry programs.
The funny thing is that this only sems to happen within an hour of the computer being switched on, like if its been on for over about and hour then it wont crash in this way (touch wood).
I have run every virus scan and spyware scan, nothing.
Any ideas guys? this is really pissing me off.