first, press ESC before it stops(if system halted, reboot and press ESC quickly)
if you can't find any missing on the screen, then, press F8 while it displays "Starting Windows 98...", and then choice "Step by step", find that when does system stops. If you still can't see any mistakes, reboot finally, when system halts, reboot to save mode command prompt, edit bootlog.txt, find out all of the "fail", then you can see...