XP Freezes on Startup

  Michendi 13:37 12 Apr 2005

This is an old problem (W2K had the same issue) that still does not seem to have a clear definitive solution.

The problem is with XP freezing on startup. Starting in Safe Mode seems to indicate that the system file mup.sys is the culprit. A quick search on the Web shows that literally thousands of users have experienced the same problem.

Suggested solutions are almost as many as the problems!!! These include - disable mup.sys (but no one has yet explained what the consequenses of that could be or how to re-enable it); disconnect all USB devices; change video cards; reinstall XP; disconnect a 2nd HDD if installed; disconnect CD/DVD drives.... None of these are really satisfactory solutions.

Now that I have joined the thousands with this problem, before I try solutions at random, is there anyone in the Forum that understands this issue and that has a technically correct solution.

A search of Microsoft reveals solutions only for W2K - with specific warnings that the solution must be applied to W2K only. Microsoft seems to have completely ignored the XP community. Even the W2K solutions are less than helpful as they consist of downloads, which if you cannot get the PC to start is a little impractical.


  PA28 14:05 12 Apr 2005

The searching that you've done would indicate that this is a problem akin to that of the old 98 shutdown issues - literally thousands of possibilities and most of them interdependant on other issues - software installed, hardware configuration - so there's really no single right answer.

This is total frustration, but rather than stabbing in the dark trying one answer after another (and, as you say, how to you go back when things don't improve) I have found in the past that the only answer is a complete reinstall. This sets everything back to zero and your software configuration should be assured.

I know that this is doesn't appear the easiest answer at the moment, but I've found that the success rate of this method is almost 100% assured - as opposed to poking around in the dark which has a good chance of making things worse.

  Yoda Knight 14:55 12 Apr 2005

I agree with PA28, except for "poking around in the dark which has a good chance of making things worse". If your considering a format things cant get much worse. If you start in safe mode with network support, you might be able to still access the net (I can), then you may aswell try the fixes off the MS site, you have nothing to loose if it does go wrong ;)

  PA28 15:33 12 Apr 2005


  Indigo 1 15:41 12 Apr 2005

Can you explain exactly what is happening, ie, how far does it get before 'freezing' what can you see on screen when it happens, any sounds that it makes, etc ???

  Michendi 17:50 12 Apr 2005

The problem may be a little more complex than I first thought.... so here goes.

1. Starting in Safe Mode. Freezes when it loads the mup.sys file, which made me think that this file was the culprit, but that may/may not be the case.

2. Starting from XP CD. Freezes when it reaches the inspection of the HDD.

3. Starting from Emergency floppy into DOS. In DOS mode a disk utility reports that the Boot Partition has been incorrectly dismounted and that there is a lost cluster. On IDE drives this would not be a big problem - simply boot into DOS and run chkdsk <drive> /f or /r.

The disks are however SATA configured as RAID. This means that you cannot run chkdsk from the DOS prompt (I certainly have not found a way to do that) but must run it from XP (after a restart if it is the Boot disk). Now assume that the lost cluster contains an XP system-critical file e.g. mup.sys. This then becomes quite difficult with the result being that the system cannot boot into Windows because of the lost system file and therefore chkdsk cannot be scheduled to run. Because chkdsk cannot run the incorrectly dismounted partition cannot be fixed.

I don't know of any other way to fix an incorrectly dismounted partition other than with chkdsk.

Hopefully someone wiser than I has another solution..:)

  PA28 14:56 14 Apr 2005

.... by now a fresh install would have seen you up and running again .............

  Michendi 09:26 15 Apr 2005

Thanks to all for suggestions. For completeness I am providing my feedback and the eventual solution.

1. For PA28 & Yoda Knight. A fresh install was not an option because Windows was unable to access the physical disk. Windows is unable to physically address a SATA/RAID disk where the first primary system partition has been incorrectly dismounted. As far as I am aware the only way to resolve this is with chkdsk/f/r. But this cannot be done from DOS as there are no DOS-compatible drivers for SATA/RAID. The Via SATA RAID drivers are only Windows-compatible.

2. Solution. (NOTE : This solution is only relevant if the first primary system partition has been incorrectly dismounted). Install Windows on a second HDD and then run chkdsk <drive:>/f/r where <drive:> is the drive letter assigned by Windows to the incorrectly dismounted partition. This fixes the problem and the first primary system partition on the first HDD is now physically addressable by Windows which returns everything back to normal.

3. Incorrect dismount. The principal reason for an incorrect dismount is that Windows was interrupted while writing to the disk. This could be caused by a power supply "blip".... which gives me a very good excuse for investing in a UPS :)

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