The system reboot automatically when it runs in the window envirnoment, it has no problem when it runs in DOS mode. Therefore, I formatted the drive, and try to install win 2000 all over again on the system, the system has no problem when it runs in DOS mode, but when the system runs the welcome page of win 2000, and then it automatically reboot, every time when the system at this stage, the system will reboot automatically. How to fix this problem, please leave me message, thks.

It sounds like you have a harware irq issue try pulling any hardware out that you don't need to boot up with Ie: modems... sound cards... cd drives... floppies... joystick controlers... get the idea anything that doesn't "need to be there" and discounnect printers also.. then boot up if it lets you reinstall one thing at a time until you find the culprit