My daughter has a Dell desktop with XP Pro. It has been rather slow for no reason that I could find. Over the weekend it started to switch off for no apparent reason. The were no messages. Now it won't even boot into Windows. When it gets as far as the message windows didn't start properly . . . and I select Safe Mode or Last Know Good Configuration the computer starts to load drivers, a screen-full, then there is a click and it switches off. With the side of the case removed I can see a green light so the power is being supplied.

All the fans work. There is a problem with the keyboard socket which is a PS2 type with an adapter for USB being loose and a message comes up "keyboard error or missing keyboard" I have changed the keyboard around with the same message so plugged the keyboard into one of the rear USB ports. The computer then accepts keyboard entry. When I removed the cover over the CPU that channels fresh air in to cool the CPU I found that one of the clips that secure the CPU unit to the board had broken but the CPU unit seems very secure.

Since these modern computers can be switched off by the software I tried to boot up using my Norton Ghost CD but encounter the same problem. I don't know whether this rules out a software problem or not.

I have wondered whether there is a problem with the power supply button and think that maybe I can bypass it. But don't know how to do this.

The PC is vintage 2003 and I could just buy another one, but as usual there is useful data on it. Not only on the hard drive but also on an additional hard drive that I fitted even though there is no spare enclosure- I just used a glue gun to secure it the bottom of the case. It has worked like that for over two years, with no problems. The second hard drive has a full backup on it.

Try Seeing if Knoppix will boot, then you can decide on Hardware / Firmware

Too many problems to mess with, especially the loose CPU clip.
Get a new computer.
Removing the data and transferring is very simple with the right adapters:
http://www.tigerdirect.com/applicati...7926&CatId=470
(USB/IDE/SATA adapter)

The broken clip you mentioned.

If it is a clip that belongs to the heatsink which clamps it firmly on to the cpu then it is an overheating problem.

Thanks for that advice. I have now tried it and Knoppix loads the splash screen then when I press enter the computer switches off. I have tried again and this time pressed F2 for boot options the DOS type screen displays and the system stays up and running but then switches off as before.

Next try: allowed the Splash screen to display longer before hitting Enter. Linus started to load then after a screen full of technical stuff it switched off again.

Last try: accessed Boot Options on the Dell by pressing F12. Set to boot first from CD Rom. Knoppix opening screen as before alloed it run then pressed Enter the machine switched off. Tried once more. Saw a message about 'passing an undefined Mode Number something to do with video? set the video to 0 and then Linux started loading but switched off shortly after.

Does this mean that it is a hardware problem and only a hardware problem?

Yep, probably the cpu overheating as mentioned by Oneder.

Thanks. Yes the heatsink can be pulled up with little effort. The plastic lug that secures the clip has broken. Could this be replaced? I can't see any easy way to hold the heatsink down

Is the CPU likely to be damaged? It also possibly explains why the machine has been running so slowly.

You will have to go to PC store to see if it can be replaced.If not then a new unit will be needed.

Shouldn't be too expensive and don't forget the heatsink paste.

Thanks for the advice. I live in England so I found another source:http://www.techfocus.co.uk/USB-Adapt...gles/TFA12.htm
Usual Rip Off Britain prices though 1£=1$ although for UK prices Techfocus is good value. This device will be invaluable if I do decide to scrap the machine.

Thanks once again