Can't remove drive letter assigned to empty drive

Off-Topic
1

I had to do a restore of Win10 because it got corrupted and after I rebooted into it -- I now have a problem.

I have a shared drive that is always assigned the letter H -- because I have several OSs on this PC and they all write to that volume by default.

But when Win10 restarted,in DirOpus, it has assigned H to an empty drive that displays using a CD icon.

I opened Disk Management to reassign the drive letter to the shared drive to H, but it won't let me because H is in use. But there is no drive in disk management showing that letter. It is not shown in the upper or lower part of the dialogue window. So, there is no way to REMOVE the assignment of H in order to reassign it.

I ran diskpart, did a listvolume -- and the H "drive" is not shown. So, there is no way to work with it using diskpart, either.

I tried temporarily removing and changing other drive letters in Disk Management, hoping that "H" would then get assigned to something I could change, but that did not work.

I opened File Explorer, but the "H" volume is not listed. It is only shown in DirOpus.

I'm using DirOpus v12.3.7 Beta x64.

One suggestion I read is going into Device Manager, show the hidden devices, and remove any device not currently connected to the PC -- but I hesitate to do that, because I don't want to have to do another Win10 restore because I trashed something.

But, if this will work, I'll try it.

Other than that, I have no idea what else to do.

2

If you configure File Explorer to show empty drives, does it appear in there as well?

Where exactly is it appearing within Opus? (On a toolbar, in the tree, in the This PC folder, etc.)

3

Try this, maybe it's similar problem.

4

Yes, it shows in File Explorer.

In Opus, it is shown in the folder tree -- using a CD icon instead of the normal drive icon.

I've tried using mountvol and get the following results:
mountvol H: /d -- system can not find the file specified
mountvol H: /p -- the device is not ready

Also, I tried the mountvol /r -- and although it did not complain or error out, it did not accomplish anything.

5

You're only tried solution described at the last post in that separate thread. Try my solution(s) maybe - I succesfully resolved that problem three times for now, so it works. Not always easy & short solution is the one that works.

6

OK, regarding that linked thread ...

I do not have a separate boot partition; instead, the boot files are located in the OS partition and that is running. So, I can not change the letter assigned to the "boot partition".

I already tried using Minitool Partition Wizard to change the drive letter of the "empty" device that is using the letter I need, and that device does not show up on the screen anywhere. I tried assigning that same letter, and was told it was in use.

Regarding the MountedDevices keys, by process of elimination, I found the device info for both the assigned letter and the shared disk device. So, I edited the entry for the empty device (the one with the letter I want to use) to change the binary code from the empty device to the shared device, restarted the PC -- and no change. The drive letter was still in use by the empty device.

So, you're saying I can remove ALL the DosDevice entries, reboot, and Windows will automatically create new, correct, ones? Or all you saying to remove ALL the MountedDevice entries, instead?

7

Suggestions here may be useful:

Nothing about this is specific to Opus, so you may find more answers on more general Windows/PC help forums with wider audiences.

8

First of all - if you have Win10 then you have separate boot partition. It's a fact. Even if you have MBR installation, Windows create boot partition. There is a way to remove boot partition on MBR installation and move BCD into main partition, but this is not a process that many people try and is not that easy (even with EasyBCD). I'm not sure is even possible in win10.

Second - you can remove all entries from MoutedDevices - Windows should recreate them.

Third (in case Minitool Partition Wizard was used) - I was wrote that first you must assign OTHER letter to that hidden/bood/whatever partition, then Apply changes, then remove that other letter, then Apply again (and repeat for every partition without letter). Then, after reboot, everything should work and mysterious drive letter will be gone.

9

I do NOT have a separate boot partition as I Upgraded a Win8.1 installation to Win10. When you do a new installation to an empty drive, you are correct that MS creates a boot partition, but since this was an Upgrade to an existing installation, it simply overwrote the existing OS partition. And yes, you can MOVE the boot loader folder and files into the OS partition, reboot, and then remove the former boot partition -- as I did that in Win8 years ago -- and I did it with EasyBCD.

Regarding the changing of drive letters, I need to use an existing drive letter that MS has assigned to former device. While that device shows up as a CD drive in Explorer, it does not show up at all in Minitool, so there is no way I can assign a letter to it, or remove the existing letter from it.

10

Ok, I understand. I don't expect that you have no separate boot partition, I though that I'm the only person here who doesn't like unnecessary partitions. :slight_smile:

Regardless - I didn't say that you should see "H" in Minitool. For some reason I didn't see that letter on comupters which have that problem too. But at least I saw some partitions without letters and I suspect (correctly) that they may be a reason. So my method works in that cases. If you have no partition without letter (on any drive) then my method will not work.

You can try to delete everything from Mounted Devices in registry (HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices - I do that when I change hard drive and motherboard for example) - that at least show you is there problem with mounted devices or maybe other program. It may be something related to virtual drive but at this point I just don't know.

Good luck anyway.

11

All the partitions have drive letters, so there's nothing unassigned that I can change.

I will try removing everything from MountedDevices in the registry and see what that does.

UPDATE: I did that, and Windows reassigned the drive letters, so although the now-absent CD drive still has a letter, it is not "H" anymore so I can reuse that letter.

12

And now you have clean (more or less) MountedDevices so it will be much easier to figure out what is wrong and find a problem.