Missing Drive Letter

  • Thread starter Thread starter Garry
  • Start date Start date
G

Garry

I noticed that a document I had open yesterday in WORD was
no longer available. I tracked the problem to the fact
that the drive the document is on has suddenly changed its
drive letter from "E:" to "G:".

Odd, I thought, but no problem...I went into the Computer
Management Console to change its drive letter back
to "E:", and it won't allow this -- there is no "E" in the
dropdown list. Yet, no other drives are set to drive "E".

This drive had been set as drive "E:" for a long time, and
no hardware changes have been made recently.

Why would "E:" suddenly not be available, even though no
other drives are using it? How do I get drive "E:" back?
 
Garry said:
I noticed that a document I had open yesterday in WORD was
no longer available. I tracked the problem to the fact
that the drive the document is on has suddenly changed its
drive letter from "E:" to "G:".

Odd, I thought, but no problem...I went into the Computer
Management Console to change its drive letter back
to "E:", and it won't allow this -- there is no "E" in the
dropdown list. Yet, no other drives are set to drive "E".

This drive had been set as drive "E:" for a long time, and
no hardware changes have been made recently.

Why would "E:" suddenly not be available, even though no
other drives are using it? How do I get drive "E:" back?
Click to expand...

Garry,

use regedit.exe to check the values in

HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices

You can delete all values in that key except those you really
need. They are automatically recreated when needed.

Apply the usual precautions when editing the registry. You can
kill your installation with the registry editor when you make a
bad mistake.

Hans-Georg
 
Thanks for this, it looked really promising, but,
unfortunately, wasn't the answer.

Firstly, I have now realised that drive E: is not
actually missing, but has been somehow hijacked by my DVD
burner (which always used to be drive "G:") -- I didn't
notice the DVD drive because, without a disk in it, it
doesn't appear in the list in the Management Console.

For some reason, the two drives swapped drive letters.
Whenever I change them back the way I want them, they stay
that way until I reboot, then they swap again.

I tried your suggestion, and checked this key. There were
many more entries than I had drives, so I deleted
everything. Upon re-boot, the drive letters changed even
more, but they changed to an order that I would expect the
OS to choose if not told otherwise (I am running Windows
XP Pro, BTW with all current SP's and patches) -- so I had
hope. I looked at the new registry entries, and everything
was much cleaner. Then I used the Disk Management plug-in
to put things the way I wanted them, and again checked the
registry -- all the same entries were there, but the
values had been swapped around amongst the keys. This
looked good so far. I then re-booted, and the two drives
swapped themselves again, although the one other drive I
had changed after deleting all the keys stayed put! Of
course, the keys for these two drives in the registry now
had swapped values.

Some further info:

The USB drive has been drive "E:" for at least two years,
and the DVD burner has been drive "G:" since February. I
can't think of anything that changed on the system between
it being OK the day before and my noticing the problem
yesterday morning. All I did was a software upgrade and
installed a few internet utilities -- none of these have
any obvious relationship to the drive system or the DVD
drive. All of the testing and troubleshooting I have done
subsequently is with these and **all** auto-load/start
software disabled. Here is what I've found so far:

If I disable the DVD drive in Device Manager and then set
the other drive (an external USB drive) to its correct
letter, the USB drive stays that way under multiple re-
boots. When I enable the DVD drive again, it is assigned
as drive "G:", and everything is hunky-dory until I re-
boot -- then they swap again. I tried deleting the DVD
drive in Device Manager, setting the USB drive back
to "E:" and re-booting -- the OS detects new hardware (the
DVD drive), installs it, and then the drive letters get
swapped again! Very frustrating.

The only thing I haven't yet tried is to physically
disconnect the DVD drive and re-install from scratch.
 
Garry,

that's a bit unusual. I've never seen drives swap letters on
their own. Never had that problem anywhere.

One thought that occurred to me is that perhaps the signatures
of these drives are, by some coincidence, similar, such that
Windows mistakes one for the other. Sounds a bit unlikely, but
then the whole story sounds a bit unlikely anyway. Are both
drives from the same manufacturer? What are their names in
Device Manager? Are they very similar?

You could try to swap the DVD drive for a different one,
preferably from a different manufacturer, at least for a test.
That would be a stupid solution to a stupid problem. (:-)

Watch those master-slave jumpers when you try that.

Anyway, you're at the source and can observe what Windows is
doing. Perhaps you can find a solution.

Hans-Georg
 
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