Windows Backup and Recovery
Troubleshooting
Errors
When booting into Safe Mode on Windows XP, it is stuck after loading the “Mup.sys” driver.
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS\System32\Drivers\Mup.sys
Solution:
Wait for Windows XP to finish booting. It first runs
chkdsk /rto repair possible corruption on the file system. This can take a long time. If the PC has a drive activity light, make sure that it is flashing. [1]
History
Bibliography
“SAFE mode bootup halting at Mup.sys.” Microsoft Learn. January 28, 2015. Accessed March 21, 2026. https://learn.microsoft.com/en-us/answers/questions/2665852/safe-mode-bootup-halting-at-mup-sys