Problem with inspiron 9100 help!

Hi, I have an inspiron 9100 and its giving me some trouble.
Everytime i use it, it boots up fine, no errors, loads windows xp and works fine for about 5 minutes. Then, regardless of what I am doing, the laptop shuts off, when I try to turn it on again, i just get the caps lock light blinking. I have to disconnect from power and take out the battery, wait 5 mins, and then I can turn it on again but the same thing happens. I check and I turned stand-by off and screen saver off but the problem still persists.
The laptop always stayed on my desk and I know that its not possible for the power jack to have come loose becasue the laptop barely left my house, it was always on my desk. I have also switched batterys and power supplies but have had no luck. If anyone has any ideas as to what the problem is, I would greatly appreciate the advice. Thanks.

 

Could be overheating. You might want to clean out the fans, the 9100 (and original XPS which was the same chasis) had issues with dust build-up.

 

I second what JTOverath said. I have the same laptop and dust clogging the fans is definitely an issue. Are the areas around the touchpad and air vents hot? Do you experience any lag issues in XP while it works?