The main reasons for this Windows XP or Win 2000 boot hang or alleged mup.sys issue are:
* Hard disk failure or corruption
* A corrupted registry or registry hive
* New hardware has been installed but not did not completely "Register or re-Register" correctly
* New hardware has been installed but it is faulty or failing
* The new hardware's driver or windows itself has been compromised (Disk data corruption or by a virus) or (rare) needs to be updated
* The power supply is marginal in output or failing (Common per user feedback)
* BIOS\ESCD\Motherboard chipset driver conflict with a component, its driver, or its registry data
* Existing hardware including the motherboard may have failed in a specific way but not catastrophically.
............................................
MUP.SYS - Software Resolutions
CHKDSK /P /R
The synopsis was that the machine would get to the Windows opening screen and before loading it would lock up,
the monitor would go to sleep and the hard drive would go idle.
By trying to load Windows XP in safe mode I saw that the system locked with the last line displayed as Mup.sys.
This file is not the issue.
By configuring my Bios so I could boot via a Windows XP Install disc, I was able to load the Windows Repair Console.
Once I received the C: (DOS prompt) I entered CHKDSK /P /R and waited for the process to be completed.
This took quite a while so be patient! The issue was that there was a bad sector on the hard disc that had corrupted
data. This bad spot was now marked and repaired by CHKDSK.
Still in the recovery console I entered the command FIXBOOT at the C:\ prompt and waited for that process to be
completed. Once that process finished, I entered the EXIT command to leave the Repair Console and rebooted the PC.
The first boot took a little while longer than normal, but when the machine came to life nothing was lost!
This procedure recovered the machine and everything is working normally.
More here:
http://www.aitechsolutions.net/mup-sys-resolved.html
Please post back if you have any more problems or questions.
If this information is useful, please mark as helpful. Thanks