Desktop

As far as I can tell, there can only really be two reasons for this. BIOS set fan controller / faulty fan, or faulty battery.

Try going into your BIOS and altering the fan speed and / or set it to automatic/variable. If your computer is shutting down without warning of loss of power, it may be that the CPU is overheating dramatically, if the fan is seezing up.

Or you have a duff battery. I had a laptop once with a duff battery, and would only work properly if it was tilted to the side.

As far as I can tell, there can only really be two reasons for this. BIOS set fan controller / faulty fan, or faulty battery.

Try going into your BIOS and altering the fan speed and / or set it to automatic/variable. If your computer is shutting down without warning of loss of power, it may be that the CPU is overheating dramatically, if the fan is seezing up.

Or you have a duff battery. I had a laptop once with a duff battery, and would only work properly if it was tilted to the side.

Well the first thing to do would be to download and install IBM's DSA which is a Diagnostic Utility and run that. That should give you an answer to what is going wrong and where to start for a repair if one is possible. Try

http://www-307.ibm.com/pc/support/site.wss/document.do?sitestyle=ibm&lndocid=SERV-DSA

For the Down loadable version of DSA and work from there.

Col

I am guessing you have not opened it yet! So, my best bet is that you have a dusty interior, more specific the fan is dusty. If the fan is dusty or the aire flow is, I am sure there is not enough cool air flowing through it. Since here temperature rises to 60, 70 or more than 90F in a few minutes. Try to stay in a very cool area or attach an office fan directly into the laptop, and It may not overheat sooner.
I have found PCs all duty, which they will shutdown in half a day, or in less than 1 minute.

Thanks for reading.

More than likely this is caused by lack of cool air. The fan can be sporadic Of/ On, Off/ On etc. See how long it ruins. if you see that it doesn't take long to shut down and your PC still feels red hot [Underneath}, chances are that's where the problem lies.
Under normal conditions a PC will feel hot, touch it at the beginning and then at the shut down point. You'll be able to tell the difference.
Take it apart, "Provided that you know what your doing" and then clean the fan and area . Then place one little drop of 3/1 oil on the pin just under the label and move the fan up and down to get the oil around. Close it up, clean it and put it back. As for the battery, don't take chances, for the money, it's not worth the trouble, just go out and buy a new one. Once installed, things "Should run a little smoother and much longer. When it shut's down and we feel anger, let's be grateful that it shut's down instead of blowing up.
Good luck
Regards
Aaron