Where are the drive letter assignments stored?

NTDEV
1

I have an XP system that won’t boot correctly. The original system was running out of disk space, so I copied the partitions to a new raid, expending them as I went. Now the new raid is failing the system activation check, so I can’t log on and do anything with it.

This is because in copying the disks, the boot disk decided it was D: instead of C:, so anything looked up by drive letter during startup is failing.

I know that D: (or C:) is just a symbolic link created by the appropriate disk driver on startup. But it has to be getting the info on which partition should be which drive letter from someplace, and I can’t seem to find where that is. I suppose in the registry somewhere, but maybe it is elsewhere.

Where is this stored?

Also, is there a way to fix this with recovery console? I can’t seem to get into the registry remotely, although I can probably mount it from a boot off of a temporary partition and hack it that way. Disk manager of course won’t let me change the drive letter for the current boot partition. If it did I’d be in fat city!

Thanks,
Loren

2

The drive letter assignments are at

HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “Loren Wilton”
To: “Windows System Software Devs Interest List”
Sent: Monday, April 12, 2004 2:46 AM
Subject: [ntdev] Where are the drive letter assignments stored?

> I have an XP system that won’t boot correctly. The original system was
running out of disk space, so I copied the partitions to a new raid, expending
them as I went. Now the new raid is failing the system activation check, so I
can’t log on and do anything with it.
>
> This is because in copying the disks, the boot disk decided it was D: instead
of C:, so anything looked up by drive letter during startup is failing.
>
> I know that D: (or C:) is just a symbolic link created by the appropriate
disk driver on startup. But it has to be getting the info on which partition
should be which drive letter from someplace, and I can’t seem to find where
that is. I suppose in the registry somewhere, but maybe it is elsewhere.
>
> Where is this stored?
>
> Also, is there a way to fix this with recovery console? I can’t seem to get
into the registry remotely, although I can probably mount it from a boot off of
a temporary partition and hack it that way. Disk manager of course won’t let
me change the drive letter for the current boot partition. If it did I’d be in
fat city!
>
> Thanks,
> Loren
>
>
> —
> Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
>
> You are currently subscribed to ntdev as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com

3

Hopefully some others will add some details here. But, on my home
system I have XP installed on D:. The install was done on top of Win
98 on C:. While the system generally let me choose my drive letters it
will not let me call my Win XP partition (actual a second drive) C:
because it says that the boot partition (the partition marked active)
must retain the name C:. I’m not sure wether or not this is relevant
to your case.

I have an XP system that won’t boot correctly. The original system was running out of disk space, so I copied the partitions to a new raid, expending them
as I went. Now the new raid is failing the system activation check, so I can’t log on and do anything with it.

This is because in copying the disks, the boot disk decided it was D: instead of C:, so anything looked up by drive letter during startup is failing.

I know that D: (or C:) is just a symbolic link created by the appropriate disk driver on startup. But it has to be getting the info on which partition
should be which drive letter from someplace, and I can’t seem to find where that is. I suppose in the registry somewhere, but maybe it is elsewhere.

Where is this stored?

Also, is there a way to fix this with recovery console? I can’t seem to get into the registry remotely, although I can probably mount it from a boot off
of a temporary partition and hack it that way. Disk manager of course won’t let me change the drive letter for the current boot partition. If it did I’d
be in fat city!

Rob
xxxxx@telusplanet.net

4

It’s a lot more difficult than it looks. You can’t just XCOPY a system
drive (of a running OS) to another drive, tweak a few settings, and be ready
to go. All sorts of things break.

The absolute best way to do this is to use a sector-based disk copy utility.
7tools.de sells an excellent utility that will do exactly what you want to
do, and will do it pretty much perfectly. No, I’m not associated with the
company in any way. But I have successfully used these tools to move a live
OS from one disk to another, and the process was extremely simple, reliable,
and pain-free.

– arlie

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Loren Wilton
Sent: Sunday, April 11, 2004 6:47 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] Where are the drive letter assignments stored?

I have an XP system that won’t boot correctly. The original system was
running out of disk space, so I copied the partitions to a new raid,
expending them as I went. Now the new raid is failing the system activation
check, so I can’t log on and do anything with it.

This is because in copying the disks, the boot disk decided it was D:
instead of C:, so anything looked up by drive letter during startup is
failing.

I know that D: (or C:) is just a symbolic link created by the appropriate
disk driver on startup. But it has to be getting the info on which
partition should be which drive letter from someplace, and I can’t seem to
find where that is. I suppose in the registry somewhere, but maybe it is
elsewhere.

Where is this stored?

Also, is there a way to fix this with recovery console? I can’t seem to get
into the registry remotely, although I can probably mount it from a boot off
of a temporary partition and hack it that way. Disk manager of course won’t
let me change the drive letter for the current boot partition. If it did
I’d be in fat city!

Thanks,
Loren

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@sublinear.org To unsubscribe
send a blank email to xxxxx@lists.osr.com

5

Thanks. No, it wasn’t applicable in my case. My case was that I had a system running off a raid with NT on C:, and I copied the partitions on the raid to a new raid using PartitionMagic. It has the clever feature of changing all the drive letters when you do this, and nicely goes in and updates the registry of the NT partition that it copies. So when I booted from the new raid after disconnecting the old raid, my boot partition was now mapped to D:, and C: became some random partion a waay the heck down in the middle of the partition list.

I ended up connecting an old drive to an IDE tail, installing a new copy of XP on that, and using regedit to go in and edit the registry on the raid install to put the partition mapping back to what it was supposed to be. At that point I could boot again and all was wonderful.

Loren

-----Original Message-----
From: Robert Newton
Sent: Apr 12, 2004 10:14 AM
To: Windows System Software Devs Interest List
Subject: Re: [ntdev] Where are the drive letter assignments stored?

Hopefully some others will add some details here. But, on my home
system I have XP installed on D:. The install was done on top of Win
98 on C:. While the system generally let me choose my drive letters it
will not let me call my Win XP partition (actual a second drive) C:
because it says that the boot partition (the partition marked active)
must retain the name C:. I’m not sure wether or not this is relevant
to your case.