Reassigning system and boot partition letters (MountedDevices)

Posted on 2004-10-13
Last Modified: 2010-05-18
Hi all, this is my first question ever in this site.

Here is my situation:

An XP Home system which had 2 HDDs. The first one is partitioned in two. The SECOND partition (physically, in the disk) is what I believe Windows calls the SYSTEM partition (contains boot.ini). The first partition is the BOOT partition (contains \Windows). I believe these partitions had the letters F and C respectively, but I'm not sure.

The second HDD failed, and I removed it. I had some more (software) work to do on the HD, so I did a full Ghost copy of it first (Disk to Image). Later, when doing some partition management with Partition Magic, I had an error and had to restore the disk from the Ghost image. That's when I my problems started. After that, I couldn't boot into the system; it gets as far as that blue screen (darker blue bars at the top and bottom, lighter blue in the middle) with the Windows XP logo in the middle. The mouse pointer sits there, as a regular arrow; I can move it. The disk LED flashes every once in a while, but not too often, but nothing else happens. If I put a CD in the drive, the arrow changes to "arrow with CD" a couple of times and goes back to normal.

I tried a repair install and that allowed me to log on, but things were not perfect: program files were not at their usual path anymore, meaning I had to browse for the executables when trying to open a data file by double-clicking on it. That led me to believe the error could have something to do with reassignment of drive letters by Windows. I tried reassigning the letters using disk management, but it won't let me do it for these partitions, since they are boot/system partitions.

I found something information on the MS KB about how to do this (, and there is a link there ( that describes a similar problem, but with Windows 2000. I was convinced that was the cause of the problem when I changed a couple of values within MountedDevices and I got, with the repair-installed copy, the same symptoms as before the repair install.

I then went back to the original Ghost image and tried reassigning letters, but this got me nowhere. First of all, I'm not even sure whether the original letters were C and F. Second, there's more drives in there; most say CD-ROM or Removable Storage (there's a zip drive in the system) in the values, but there is one (M:) which has a similar value to the others. It's probably just from the old drive which was removed, but it is another thing to add to the confusion.

The real reason I'm posting this question, then, is to know if there is a surefire way of knowing which values (which, I believe, correspond to disk signatures) should be assigned to which drive letters.

By the way, I'm booting through the ERD Commander CD to edit the registry.

Thanks in advance...
Question by:zabumba

Accepted Solution

zabumba earned 0 total points
ID: 12302499
Ok, I got it working, after some 10+ hours of trial and error...

To make the story short and simple, in the end it boiled down to putting the HD on another machine, recording what values (i.e., signatures) were assigned to each drive letter under MountedDevices, putting the drive back on the original machine, booting to ERD and putting those values there. I did a bunch of other stuff, like fdisk /mbr (from a DOS bootdisk) and fixmbr (from Recovery Console), but bottom line is I needed to get the right signatures into the registry (of course those procedures erased and recreated signatures, but that doesn't matter, they didn't need to match the original ones).

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