MyPCHealth

Windows XP just restarts on Windows Xp loading screen and Safe mode hangs on Mup.sys – Safe mode stops on Mup.sys – safe mode automatically reboots a few seconds after Mup.sys

I had this problem on a windows XP machine and I trawled the forums and web pages looking for fixes for the solution. I will list some of the fixes that people suggested. These did not work for me but there is no reason why might not work for you. Then I will list my solution to the problem. You will need to be reasonable level of proficiency with computers to attempt some of these fixes. Before trying anything please read our disclaimer at the bottom.

Option 1. – Try a different power pack

It has been suggested that this error can be caused when new hardware has been installed where additional power is required or the power pack is losing its ability to run the computer. Although this has been the fix for others, I dispute its validity. It’s worth looking at to cancel out all potential issues.

Option 2. – Run Chkdsk /p in the windows xp recover console

• Put your Windows XP cd in the drive and boot to it. (if it doesn’t allow you to boot. Check the boot order in the bios)
• Press “r” to choose the recovery console
• Select the windows installation. “1” then [Enter] if you don’t have multiple operating systems installed
• Then enter the Administrators password ( if you unsure it maybe the default that is normally blank [Enter] )
• Type chkdsk /p then press [enter]. it should run some tests on the files and disk. Type exit to reboot the machine. If it’s not fixed try option 3

Option 3. – Reinstall Mup.sys file from Windows XP CD.

• Put your Windows XP cd in the drive and boot to it. (if it doesn’t allow you to boot. Check the boot order in the bios)
• Press “r” to choose the recovery console
• Select the windows installation. “1” then [Enter] if you don’t have multiple operating systems installed
• Then enter the Administrators password ( if you unsure it maybe the default that is normally blank [Enter] )
• Type: expand d:\i386\mup.sy_ c:\windows\system32\drivers\mup.sys

(where d: is the letter of CDrom drive)

• then press[enter]
• It should say it has copied the file. Type exit to reboot the machine.

Option 4. – How to recover from a corrupted registry that prevents windows XP from starting

To do this it’s best to follow the Microsoft’s guide. http://support.microsoft.com/kb/307545/top/en-us

The steps involved are:

• Backing up of registry (important as If this does not fix you will need them in my next step)
• Loading clean versions of the registry to allow to boot into safe mode (you will have lots of problems settings, software drivers so it will be unusable in this state)
• Copying reg files from a system restore image.
• Boot back into recovery to load the Reg files from system restore image.

If after following inserting the clean registry files you still cannot boot to safe mode there is a serious problem with your XP install (which was my case) Follow the next part :

Option 4a – reinstalling windows over the top reload old registry files. (Solution to my problem)

Before you go through these steps you must have followed Microsoft’s guide and created a backup of the registry files. You will have them located and names as follows if all is correct:

c:\windows\tmp\system.bak
c:\windows\tmp\software.bak
c:\windows\tmp\sam.bak
c:\windows\tmp\security.bak
c:\windows\tmp\default.bak

Ok so we can start.

• As we are installing windows over the top it is worth copying out your personal files. To do this you can use a Linux system such as Knoppix (http://www.knoppix.com/) that runs off a CD. You boot to that OS that’s on the CD and you can copy files off the computer with ease to a USB memory stick or hard disk. If you require more information see http://www.mypchealth.co.uk/GuideRecovery.php Option 3
• Once you have them backed up we can get on with recovering the windows installation.
• Put your Windows XP CD in the drive and boot to it. (if it doesn’t allow you to boot. Check the boot order in the bios)
• First Screen “Welcome to setup” press [enter] to install new copy of windows xp
• Next screen press F8 to agree to the terms and conditions
• Next screen press r to repair the windows installation. (you will require to re enter the product key later so have it handy)
• Once windows has installed it should boot. None of your settings will be correct and software will not work because of the new registry. So now we need to reinstall the old registry files. Cannot pull them from a system restore as reinstalling windows deletes them.

Putting back the old registry will likely bring back any viruses/spyware and malware that may have caused this issue in the first place so virus cleaning, registry cleaning will all need to be performed afterwards.

So to put the registry back :

• Put your Windows XP cd in the drive and boot to it. (if it doesn’t allow you to boot. Check the boot order in the bios)
• Press “r” to choose the recovery console
• Select the windows installation. “1” then [Enter] if you don’t have multiple operating systems installed
• Then enter the Administrators password ( if you unsure it maybe the default that is normally blank [Enter] )
• At the command prompt, type the following lines, pressing ENTER after you type each line:

del c:\windows\system32\config\sam
del c:\windows\system32\config\security
del c:\windows\system32\config\software
del c:\windows\system32\config\default
del c:\windows\system32\config\system
copy c:\windows\tmp\software c:\windows\system32\config\software
copy c:\windows\tmp\system c:\windows\system32\config\system
copy c:\windows\tmp\sam c:\windows\system32\config\sam
copy c:\windows\tmp\security c:\windows\system32\config\security
copy c:\windows\tmp\default c:\windows\system32\config\default

• Type exit to reboot the machine.

When Windows loads you need to get on the case and install Antivirus software, antispyware, windows updates and registry cleaners. Some other pieces of software that you previous had may have problems so they may need reinstalling. But fingers crossed most should be ok.

Good Luck