I've had my laptop for just over a year and I've had this problem pretty much from the start. It gradually happened more frequently as the year went by, it also started crashing sometimes too. A couple of months ago it wouldn't start up, I got it to do a system restore, but everytime it was shut down or went to sleep it wouldn't start up again. I took it back to PC World and they sent to Asus to be fixed, they reckoned the cause was a faulty hard disk, so they replaced it. I've now had it back for about 3 weeks and it just suddenly switched off again, so it obviously hasn't fixed that problem. When it goes off there's a squeak as if the disk is stopping suddenly. There's no pattern as to when it happens, and I'm often not really doing much with my laptop. It's not overheating, it never tends to get particularly hot. I'm now at a loss as to why this is happening. It's so random that it would be impossible to show it someone when it happens.