What was the last thing that happened before this error came up? Did you install any new hardware?
There are several things that can cause similar behaviour, depending on when exactly this behaviour starts.
(1) If this happens RIGHT before the operating system is supposed to start up, then it could be a boot-sector virus, or your operating system's boot-up files may be damaged. To test this, boot with a normal Windows boot disk (write protected, of course) and if that works, it means your operating system is not well.
(Does the floppy drive's light go on before the computer hangs up?)
(2) If this happens while it is still performing the BIOS' POST checks, it could be some malfunctioning hardware. This can be tested by
(a) Removing any recently installed computer hardware
(b) Load failsafe or default options in your bios configuration.
Try these few things, and if it stilld doesn't work, I'll scratch head some more
Regards,
FolkLore