|For what's it is worth: I was hit with the mup.sys freeze right after using media player. My browser (IE8) began directing web pages to a variety of marketing web pages. I have XP, and service pack 3, as well as paid editions of Superantispyware and Malware bytes. I ran scans and found several pieces of malware and trojans. The scan picked them all up. I tried to go into safe mode to run another set of scans and that is when the mup.sys freezes began. Although my browser "worked" it would still occasionally fix to other ad pages. Scanned again with SAPW and MB and both came up clean. Tried Combofix and it showed nothing.|
I read all the boards I could find and disabled all external drives, usb and everything else. The safe mode boot still stalled at mup.sys. I even let the laptop "sit" on the safe mode screen for 3 1/2 hours in the hopes that time might at least get me into safe mode so I could scan whatever was still there. The screen did not budge.
In desperation, more than anything else, I loaded up Microsoft Security Essentials and scanned the computer. It found 5 trojans that are relatively new (all listed as late 2009 or 2010). It removed all five. I rebooted and safe mode popped right up. The computer is back to regular speed and works like its charming self.
This may not work for everyone, but give Security Essentials a try (it's free on microsoft support). Thanks