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I have a Windows XP Professional desktop. Until today everything was running fine. This morning when I restarted the machine, I could see the Windows XP initial screen; the progress bar kept on moving as if it was trying very hard to load something. A black screen then appeared. I tried to use safe mode but that gets stuck booting when it tries to load MUP.SYS.

I've looked through various articles but almost all of them keep talking about the recovery console. The problem with me is that in all cases, the bootable CDs do not work. As soon as I try to do from one of the CDs, a black screen appears which does not take me any further.

Any suggestions what could be wrong?

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migrated from Sep 6 '11 at 1:37

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Tap F8 before windows starts loading and select Disable Automatic Restart on System Failure, then post if there are any changes or more info – Canadian Luke Sep 6 '11 at 2:11

Check your BIOS to make sure CD booting is enabled, and is above the hard drive in the order it's supposed to boot. It's pretty much impossible to troubleshoot a system if you can't do anything at all.

It's not actually mup.sys that's at fault; it's one of the things that comes after that. Quite often it's due to bad RAM, so I'd suggest trying to run memtest to rule that out. If it's not RAM - and you can't enable CD booting in ANY way - it's pretty tough to investigate. If it's RAM, remove the offending stick and try booting.

Otherwise it's a driver of some sort that's loaded after mup.sys.

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if it was a faulty ram, there should have been beeps before i booted into the system , right ? also if was ram, the windows loader should not have come up, right? How do i run memtest ? there is no console window that i can access . I cannot access any bootable cds nor can I access the command prompt from the safe mode . – user96781 Sep 6 '11 at 2:31
not always -some ram errors don't trigger it off. and if you can't get bootable cds working, or without some form of recovery console or safe mode.. you can't do anything, really. – Journeyman Geek Sep 6 '11 at 3:47
I'm seconding the point that faulty RAM will not always make beeping noises on boot up. – user3463 Sep 6 '11 at 6:20

I've had something like this happen before. Something got corrupted in the XP bootloader. The stupid thing about the Windows XP CD is that sometimes when something is awry with the bootloader on the hard drive, the CD won't boot! The stupid CD is looking for something on the hard drive and hiccups if it doesn't like what it sees. Even Windows-based rescue CDs like UBCD4Win won't boot. But if you format the drive it works. Weird.

You should reformat and reinstall. But first you'll need to copy your files onto another disk. Boot with a Linux live CD such as Ubuntu, Fedora, or Parted Magic, and copy your important files onto an external hard drive or USB flash drive, make sure to do a "safely remove" of the external drive, and check on another computer that the files were actually copied and are readable by the other computer. Even though Windows won't boot, you'll have no problem booting with a Linux CD, unless you have a strange problem in your BIOS or hardware.

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