Found this after a google of mup.sys. :)
So, we started scouring the Internet looking for other possible causes. We found quite a few instances of the "hung at Mup.sys" symptom, but with a variety of fixes. Several administrators solved the problem by replacing memory. Several others solved it by replacing drive controllers or by simply moving the controllers to a different slot. One administrator even replaced both processors. Then we found a posting by Sean Branham at the Annoyances.org web site. See the full text of the thread at http://www.annoyances.org/exec/forum/winxp/t1047532372. Sean correctly determined that the cause of all these disparate "hung at Mup.sys" failures were actually caused by problem with the Extended System Configuration Data (ESCD) stored in the system BIOS. The ESCD maintains a static list of Plug-and-Play resource allocations. This avoids recalculating all the allocations at each restart. If the ESCD gets corrupted, then the operating system cannot assign resources correctly. Windows makes this resource decision just after it loads the Mup.sys driver because that's when it loads the Advanced Configuration and Power Interface (ACPI) drivers. You can download the (mercifully short) ESCD specification from http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/escd.rtf. Once we knew that something in BIOS might be causing the problem, solving it was a snap. We downloaded the most current firmware revision from Dell's web site and flashed the BIOS and that was that. (Some motherboards come with an ESCD rebuild option in CMOS, so it would not be necessary to flash the BIOS.) The system booted without a hitch and performance was right back to where it had been before the problems started. If it hadn't been for Sean's insight, we would have spent time and money replacing the PERC controller, which unfortunately might well have solved the problem because replacing the board would have refreshed the ESCD. It's difficult to determine whether the system crash earlier in the week caused the ESCD problem or vice-versa, or if some other problem caused both. At this point, Anon is going to keep an eye on the system and hope for the best. I'd like to thank Sean both for solving this tricky problem and for taking the time to post a detailed account. This was the first time I'd visited the Annoyances.org web site, and it looks like a great resource. -- JRS steinie**[email protected] Please remove **X** to reply... Facts do not cease to exist just because they are ignored. ________________________________ From: DHSinclair <[email protected]> To: Hardware Group <[email protected]> Sent: Monday, February 2, 2009 2:37:03 PM Subject: [H] ?small problem Have what seems to be a small problem. WXPproXP3...... Was an Upgrade from W2KproSP4..... Otherwise works superb! But, Can Not boot to Safe Mode...........Hangs at "mup.sys". Do have reading for this, but, am wondering if there may be something else going on? My network connection pointer in the CP is at #2. In the past, I have found that #1 was never totally ripped out............ :) I do not recall how to fully erase net connections, if this is what is going on........... I have sat for 40+ minutes waiting, at the blue (Windows is Starting) screen trying to do a Restore Install. Not yet..... I really do NOT wish to erase/reformat my C: partition; UNLESS the Collective convinces me this is the ONLY way. Hmmm. Perhaps Windows CAN NOT really be Upgraded? Sure looks like it at the moment. This is NOT a call to Resurrect. I am not Down. WXP is fully running (and I remain totally confused!) If this is a "boot.ini" file trouble, I can read/correct. (?) If this is a "mbr" partition error, I can read/correct. (?) Where to start? Ideas? Suggestions? Opinions (except Vista) welcome? Duncan
