It happend often Windows XP to just stuck in loop reboot in all possible modes (Safe mode, Safe mode with networking, Safe mode with command...etc.).
During trying to boot in safe mode the computer stops at file mup.sys hands there or right away reboots when it reach this file.
In my cases removing the RAM booting and then setting the RAM back helped at 100%.
Hope it will help you to.
Best regards,
Stoyan Bukovich
Executive manager
SNB Solutions
Cell.: +52 6241 616969
E-mail:
s.bucovich@snb-bg.comWeb:
www.snb-bg.com