It's funny i read all this fixes and i think someone needs to start a new form because..for example...the last post covers about 10 different problem fixes. Not to say it isn't helpful but i think the first step if for people to find out what is truly wrong with there computer. First try turning of auto reboot on errors in your bios see what blue screen comes up (maybe depends on what’s wrong with your computer after mup.sys loads) you'll might get some kind of Fatal System Error like stop: c000021a. For me it was the c000021a which is a missing device driver dependency. Once i fix that I’ll post how i did it. But i would recommend trying to find out what is actually wrong with your computer and post that because as of right now every post with a possibly fix is a trail and error type of fix. Maybe by seeing what is wrong someone can post a fix for that problem.

That post covers a bunch of things because a bunch of things can cause the same signature that this post is addressing: To wit: The system hangs at the XP logo screen during a normal boot attempt. If you boot into Safe Mode, you'll see all the support files being loaded until it gets to "mup.sys" and then the system will hang. Since the offending event is whatever comes right after mup.sys, but you never get to see what that event was, it's tough to figure out where to start with the troubleshooting.

Without some clue where to start, you're stuck trying random things. The previous message attempts to give folks a leg up by providing a systematic list of things to try. The idea is that at least one other person who's suffered from this signature has had success from each of those actions, so they're worth a shot.

If there were some way to get the system to clearly explain what error is causing the problem, then yeah, maybe this would be a dumb post. But there's not, so it isn't.

If you actually saw a blue screen error message, then you have a different failure signature than the one this post is addressing.

Jim

I'm not saying it's not helpfull i did all of those things and i think it's a great start but...i do hang on mup.sys like everyone else here and non of these fixes will help me. I just posting for the people who the fixes here don't work for. That a more technichal aproach might have to take place.

Hey, if you can develop a more systematic way to troubleshoot this error signature, more power to you. I hope you share it with the rest of us.

By looking at that list, it's obvious (to me, anyway) that there are a great variety of things that are seemingly completely unrelated from each other that various folks have reported as being the source of the problem for them. It is by no means advertised as "your problem must fall into one of these categories". It's just a list of things that have been reported.

Because the signature most folks have seen is one in which there is NO information available to help determine where to start troubleshooting (i.e., most people get nothing but a hung screen--no error message, nothing in a log, etc.), and because the folks who have reported "fixing" this problem have reported a variety of things that worked (which resulted in the list you're referring to), no one has been able to figure out a more systematic way of approaching the problem than a list of "this is what worked for others, so we offer it as a place to start if you don't have any better information available." (Thanks to Bryan for compiling that list, btw!)

If this list doesn't work for you, then I offer you "good luck", and hope that when you solve your particular problem, you'll report back on what worked for you so that we can add yet another line to the list. Or better yet, that you'll be smarter than everyone else here who's tried to muddle through this, and can provide a systematic approach to solving the issue that will work 100% of the time. (Your suggestion to turn off "auto reboot on errors", for instance, would do nothing for me or most of the other people who have reported this problem, because our systems were not getting a blue-screen error and rebooting; they were hanging at the black Windows logo screen with a seemingly-infinite repeating animation of blue dots marching along under the logo. In my case, it would eventually boot after 15 - 150 minutes of sitting there, but for others it never did.)

In my case, the problem was a flaky IDE cable. There was never any error message. Once the machine booted, I could access those drives okay, and it never occured to me that that was the problem. Only by randomly choosing to unplug my IDE devices and then plug them back in one at a time was I able to diagnose the issue. There *was* no "more technical" way to solve my problem, because there *was* no error information that presented a trail for me to follow.

Sorry if this sounds defensive. Keep in mind that this entire thread is nothing more than a bunch of amateurs each offering what they can to help others try to tackle an annoying problem. Writing a note that essentially says, "You guys are not completely unhelpful, but you really need to do better," is not likely to elicit a sympathetic response.

Jim

The reason why this problem is so hard to diagnose is that the indicator is so faulty. Mup.sys is the last thing to load before the system starts allocating resources for final boot. That means that it will hang here if there is a problem with Any piece of hardware, or any misconfiguration of hardware, faulty devices, faulty Bios settings that interfer with windows specificaly ect. This is in the realm of "I pushed the power button on my new computer and nothing happened". What you see is only a small indicator of what the issue truely is, and the solution could be one of three hundred things. There will not be any cold cut solution to this issue, but I can pretty well assume that its A Hardware Issue, Hardware Configuration issue, or a Bios Issue.

Amen to hardware problem.

This could be an epic, sorry for the length, but some may be useful. I've read this entire forum, because Mup.sys was the only clue I had, and there's some great info here. My situation points to a hardware problem as well, as I just shipped my PC... however, there are some interesting tidbits that may be of help:

Scenario - A7N8X machine has been running fine for about 2 years with a PS/2 keyboard and a USB 2.0 mouse at home. I went on work travel and bought a new (USB 2.0) keyboard and I ran just fine for about 4 months with a USB 2.0 keyboard and USB 2.0 mouse. After I return home, I plug in my PS/2 keyboard and everything seems to be working fine, except that when playing a game, I any keystroke cancels the key that I'm holding down (e.g. if I'm holding W and hit any other key, I'm no longer moving forward). I need this functionality, so I set up to fix the issue.

Attempt 1: I go buy a PS/2 to USB adapter (split adapter by Dynex). I adapt my PS/2 Keyboard to USB and leave the USB mouse in its own slot. Same problem.

Attempt 2: I check dxdiag for input device anomalies. Everything looks fine so I move on to Device Manager (DM) and check the keyboard/usb root hub drivers. They are much outdated. I download some crap 5.5 keyboard software/driver from microsoft (I've never had to download a keyboard driver in my life), install and reboot. DM still shows "HID Compatible Device" so I go in and manually choose "Microsoft Natural Pro USB" <reboot> Same problem. I go into DM and remove the interface devices and reboot (how, you may ask? I have my power button set to soft off)

This is where it gets ugly...
New Symptoms: The machine reboots just fine a few times, as I'm toying around with driver settings in the DM, and nothing is fixing this problem. As the machine reboots for the 10th time or so, with the usb mouse and keyboard (adapted), I get to the XP login screen and find that I can use the mouse, but I can't type anything with the keyboard AT ALL.

Attempt 3: I shut down the PC and lose the keyboard adapter, and plug the keyboard directly into the PS/2 slot again. This time, I'm tapping the numlock key to see just how locked up I am. I still have the USB mouse plugged into a live USB slot, and everything seems to be running okay until I get to the XP login screen again. Then the keyboard numlock goes insanely squirelly as I try to tap it on and off. It's dim, then it stays on when I tap the numlock a few times, then it acts normally. This obviously leads me to believe that this is now a hardware problem, and that it's possible that this USB adapter had a short in it and fried my mobo. sooooooo....


Attempt 4: I try to boot into regular safe mode so I can attempt to remove everything from the DM and see what XP has to say about how hardware should be handled, but I can't log in, and the machine keeps hanging on mup.sys. This is when I come here, and find more goodies. Between steps 3 and 4, I also tried resetting the bios to default and flashing to the most recent version with no luck.

Attempt 5: I grab my XP disk and go into recovery mode with the same setup (PS/2 keyboard and USB mouse -- it should be mentioned here that any attempt to use the USB adapter for the keyboard is utterly failing, by the way). Once in recovery mode, numlock works fine, I can type all I want, and there are no issues whatsoever with the keyboard. This is when I try the chkdsk /p. It found some issues, but I didn't realize that /p doesn't repair, so I'm currently trying this again.

Attempt 6: I tried resetting the ESCD settings in the BIOS, and that didn't work.

Basically, I'm smack-dab in the middle of troubleshooting this problem and these are my next steps:

1. Run chkdsk /r (in progress)
2. Find a native USB keyboard to test USB with.
3. Attempt to recover registry, or re-install WinXP over the top, trying to salvage apps and data.
4. Attempt to salvage apps and data and do a full wipe
5. Start replacing hardware (note: I know this is the most likely culprit, but I just don't want to face up to the fact that something may have failed. I have a lot of expensive hardware in there, and I'm not really interested in replacing it at the moment.)

Anyway, if anyone has any insight, I'm all ears, and I'll let everyone know when I figure it out. The only times I've ever had this much trouble with a keyboard, we basically just replaced the mobo and the problem went away. However, with XP SP2 and USB 1.1, 2.0 and PS/2 all involved in the mix, I'm inclined to exhaust my software options before swapping out hardware pieces, since it seems that DOS-type interfaces don't exhibit this keyboard problem. Hope this helps.

dd

DD -

What does that have to do with mup.sys?

Specs:
i recently purchased my parts all new accept for cd rom. socket 939 AMD 3500+ 4gig ram, 512 atix800, 2x200gig sata HDDs... pioneer dvd burner.. Nforce4 SLI motherboard... running PCIX

FIXXED
ok guys this is what i done to resolve what i thought was hardware malfunction or Disk corruption...
after having read all post here, which were very helpful. My PC had been built for 1 week and i was setting up my pc area as i have several monitors and pcs on my desk. i ran some benchmarks and then shutdown unplugged all and put it wherer i wanted, then after plugging it into my DVi input on my monitor i noticed it didnt boot, thinking it was mearly a grafic setting for my monitor (as it is 106cm) i plugged it into my old Cft monitor to change some settings and it didnt bootbeing late i was frustrated and left it to the next day..

now after several boots it was freezing in the same spot every time on mup.sys.

i started to go over what i had done and all i could think of was i tapped it slightly not normally enough to make any impact what so ever, when i was placing it down.. and also i got a slight shock off it serveral mins after it was unpluged and moved...

so after trying chkdsk, sys recovery, serveral reinstalls on differrernt drives, unplugging usb and cd roms disabling many things in BIos i read that someone reset there CMos...

Thinking it wouldnt achive anything but at this stage was willign to try anything i done so..
And Bam it was fixed so thanks to you all for all comments and i hope this helps
(also i installed SP2 teh night before for anyone going through the process of elimination)

Dont know if i done it correct or not but this is how you do it if you dont alrdy know( quite simple)

on your MB You will notice i battery liek an oversize watch battery. with everything unpluged and your have earthed yourself ( just uincase) simply take it out, plug monitor in and KB and Power and turn it on...

the screen should display you have nothing installed NO HD no nothing,,,

unplug it all again and put teh battery back in.. and hopefully you will have the same luck i did..

DD;

DD writes: What does that have to do with mup.sys?"

Absolutely nothing. If you examine all of the empirical data presented not just here but in every forum where this issue comes up. You will deduce that this problem could anywhere from the ESCD to the HAL to an unsigned driver, etc. I opine that this issue lies beyond "mup.sys" (as most do now) and that's a big issue. In this forum, you'll find an earlier post that seemed to fix my problem. But, I'm amazed at what other have done to remedy the same issue.

From my experience, as an engineer, I've never seen issues like this with other hardware architectures and OSs. I believe that the only way to observe this anomaly is with an ICE and and proper debug software. Enough of my diatribe. It just angers me that Microsoft ( at least to my knowledge) hasn't said a thing about this issue. But I do know what a tier one or tier two support engineer would have you do to try to fix it and it looks like you're almost there.

Wayne

i agree with you bro the complete randomness is stupid, it amazes me sometimes the errors that i encounter when fixing pcs andsometimes what seems to be same error from outside is never that, but as i would expect my reply would look fairly similar to rest, but if you are like me it it is all about the process of elimination and if i have learnt anything from years of pcs it is that nothing is waht it seems and sometimes the most unlikey soulution can sometimes work..

what did my reply have to do with mup.sys everything and nothing

Nothing in teh fact that what causes this problem is beyond me as i went from thinking it was hardware then software then blank

but the Everything part is what lead me to this forum, and this helped me do other things i had not thought of doing, so in regards to the relevance of mup.sys as far as i am concernd it is just a way of getting us togerther to try figure the problem out for them

anyway hope it helped

good call wyane, F U Microsoft

and if u read my specs from my earlier post someone metioned earlier that this shouldnt effect 2K systems but as you can clearly c it does,

Ahhhh!
Mup.sys is not the problem. This is the driver for the Multiple UNC Provider, this determines the network client protocol to use when the target server is specified by a UNC path. During safe mode boot, the system displays each driver as it is loaded, so the fact that Mup.sys was the last driver on the screen prior to the system hang indicated that the problem was with the next driver... Catch 22 cant see it You could use recovery console and look at Ntbtlog.txt. Probably will not find it.

MICROSOFT:
This problem may occur on Advanced Configuration and Power Interface (ACPI)-compliant computers that use Advanced Programmable Interrupt Controllers (APICs) if the computers use the ACPI RESET_REG method instead of using the keyboard controller to restart. see http://support.microsoft.com/default.aspx?scid=kb;en-us;822624
However microsoft solution always seems a little more complex than needed.

Some motherboards come with an ESCD rebuild option in CMOS and you could use that To restore The extended settings. Or Battery out or CMOS Reset etc BUT ...

All I did was to go into the bios settings , Advanced Chipset settings and ensured that APIC was ENABLED. The system then Worked . I could actually get it to fail again by disabling APIC !!!

I don't thing this simple step will work for everybody, It would however be interesting to know for how many this solved the problem

Yes, the ECSD reset solution has worked for some--that's why it's #3 in the list of things to try at the top of page 7 of the replies to this topic. (For what it's worth, it was one of the things I tried, but it didn't help in my case.)

(And this thread has repeatedly established that mup.sys itself is generally not the problem; it's just the signature that the user sees, and about the only thing to key off of when resorting to Google to help find a solution, which is why everyone keeps referring to "the mup.sys problem".)

ok I am dealing with this same issue, a search on google of mup.sys lead me here.


My computer was running fine but I was doing a hardware upgrade. Adding a Barton XP 3000 CPU and 2 gigs of DDR 400 ram. I decied to install the ram first and then do a test boot. When I booted up the computer was stuck at the loading screen, I found out I could only boot into safe mode with out network support. All other option resualt in windows crashing.

I tried putting the old ram back and still had the same issue. I tried a few of the fixes listed here including resetting my comos battery. Which has resualted in the computer nolonger even booting in safe mode.

I've tried to reinstall windows but everytime it ends up with a blue screen of death with the "top 0x00000051 REGISTRY ERROR"

BTW now when I try to boot into safe mode I get a missing system file error..

I'm letting the computer sit right now with the battery totally out, the memory is out and everything is a unplugged. I've also tried pulling everything off the mobo in hopes it may reset something.

I'm still with out any luck, anyone have any suggestions?

I had switched memory sticks when I started having the hangup at mup.sys on my Win 2K machine. Even after I put the original stick back, it kept freezing either in normal mode or safe mode. After doing a google search I ended up here and after some reading I went to DM and removed some hardware that had problems that I had left alone. After rebooting it came up fine and hasn't given me any trouble since. I have noticed that several others with the hangup have had success with resetting CMOS or BIOS. The one common thread I have noticed is that whatever the actual problem is seems to center around some type of hardware issue. Again, notice that it happened on my Windows 2000 Pro SP4 box, so it is not an XP SP2-only problem. So far my "main" box which runs XP Pro SP2 has not had any problems hanging on boot, even though I have made hardware changes since SP2.
I certainly hope Microshaft is more forthcoming with help soon. Good luck everybody.

EASY Fix. I had the same problem on an XP machine. It froze at the mup.sys when trying to boot in safemode.

Put your XP disk in and go to recovery. At the C: prompt, type fixboot.

When I did this it said my boot sector was corrupt and created a new one. Booted right up after that. Try it first!

Sarah

No offense intended Sarah, but it was the first thing I tried too . Glad to hear it worked for you.
Alright everyboby, I guess we've got a hundred or so things to check for without a wimper from either Microsoft or their software.

Wouldn't ya just like to see:

PANIC: System haulted bad sector 0xXX on boot. Device YYYYYY!!!

Or modprobe failed while adding module: XXXXX.

or something.

Better then a little ball rolling back and forth - ad infinitum.

I just encountered the problem last few day at my friend's desktop and I able to solve it by boot from Win 98 Boot Disk and re-installed Win XP Pro. However, wiht this method it erase all my friend's data in the PC. I have another friend is having the same problem, and he need to secure his important data in the Notebook. I have tried all the method I used to secure desktop, now I have no idea.

Any help on this will be much appreciated.

Thank you.

Assuming putting back the old ram did not fix things I would suggest:
1. Follow Sarah's suggestion about the recovery option using the WinXP disc.

2. BIOS reset... but take note of the multiplier settings if your CPU multiplier is edited via the BIOS and not by manual jumper settings. Sadly if the BIOS automatically detects the RAM speed I doubt if this will solve your problem.

3. If you have a spare powersupply unit lying around preferably with same or more wattage than your present unit you could try it on your rig. BSODs are very typical for a powersupply no longer able to supply the needed juice (in my experience at least for Windows98SE, ME and XP).

When I encountered the mup.sys problem, I tried all the solutions listed in the boards and made the mistake of doing the fixmbr (a suggestion of one post) and in effect rendered my drive non-functional thus requiring a format. It worked for 3 days then froze at the boot up screen being a bit faint. On safe mode it again was locked up on mup.sys. Good thing I had an extra powersupply unit and after installation, the desktop unit has been working fine for almost 3 weeks now. The old powersupply unit was 300 watt and the new one is a 400 watt unit.

al
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David E Jul 06, 2005, 03:40 PM Message - Profile - Add Buddy - Alert Moderators
Re: Windows xp freezes at mup.sys
ok I am dealing with this same issue, a search on google of mup.sys lead me here.


My computer was running fine but I was doing a hardware upgrade. Adding a Barton XP 3000 CPU and 2 gigs of DDR 400 ram. I decied to install the ram first and then do a test boot. When I booted up the computer was stuck at the loading screen, I found out I could only boot into safe mode with out network support. All other option resualt in windows crashing.

I tried putting the old ram back and still had the same issue. I tried a few of the fixes listed here including resetting my comos battery. Which has resualted in the computer nolonger even booting in safe mode.

I've tried to reinstall windows but everytime it ends up with a blue screen of death with the "top 0x00000051 REGISTRY ERROR"

BTW now when I try to boot into safe mode I get a missing system file error..

I just ran chkdsk /r on my drive and that fixed it.

Using the XP recovery console from booting with the xp cd.