I am putting this information on the Net so that others can benefit from this. I wasted almost 5 years finding the problem !! (yes, even problem) and the solution.

Problem: Compaq Presario 1800 laptop - when upgraded from its original Windows 98 (to Win2K, XP Linux etc) started having display problem and the computer hung all the time after every few minutes. No new drivers from ATI for my ATI RAGE Mobility card, no harware repairs came to my rescue.

Solution: Installed Windows XP, went into Display Properties-> Advanced -> Troubleshoot. Checked off the Enable write combining. Amazingly, the problems were gone and my dear laptop started functioning properly.

Hope this helps to at least one soul on this earth.

Rajesh Dixit

PS - By any chance if some one can confirm that the problem will be gone for other operating systems by upgrading my Video card to a better version. Please leave a note.