My PC has developed a fault where it switches itself off for no apparant reason. It started today and so far has switched itself off 4 or 5 times. When it does switch off, it won't always boot back up straight away, you press the power switch it comes to life for a few seconds and then dies. I'm pretty sure its not software related, as when it doesn't boot up, it doesn't even get to load any software before shutting down again. The computer is almost 5 years old and has the following spec. Built by Alienware: AMD Athlon XP2200+, 1.8ghz Asus Motherboard 1024MB Mem 120gb HDD extra 160gb HDD that I installed a month ago Windows XP Service Pack 2 NVidia GForce 6600 graphics card Creative SB Audigy Card It has 3 fans (sounds like an aircraft) and is definately not over heating, as it is very cool inside. I have read that this type of fault is usually down to a faulty or old PSU. Also the computer clock is always out by a few hours when I switch it off, which I am told is down to the little battery on the motherboard being dead. I have disconnected my HDD that I installed, as I had to daisy chain the power from the other HDD and it still switches off. I'm thinking it could be the PSU and will probably end up taking it to the local PC Repair place, but they want to charge me £45 +VAT to look at it. I don't know what PSU it has at the moment, but as it was built by Alienware it shouldn't be a cheap one. The computer has been running for almost an hour and not switched off, but I know it will happen anytime now.