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machine: Windows 8 64bit, single user with admin rights

I've probably used subst to make a new Q: virtual drive for my C:\portableDrive folder. Now I can't see it when I type "subst" command in the cmd. The Q: is not a mapped drive (via "net use" command) neither is it present in the disk management. Where could be the problem?

screenshot - edit: maybe similar issue to this one - Unable to unmount "subst" drive

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@Mokubai His space on Q: shows Drivespace and freespace (same as C). If it is the virtual Q-drive Office 2010 creates its not accessible and doesn't show space (according to the screenshot in that topic). – Rik Sep 15 '13 at 15:39
up vote 2 down vote accepted

I see in your screenshot you are running cmd (the command prompt) elevated (note the "Adninistrator" before the C:\Windows\system32\cmd.exe). But if you did the original subst as a user it won't show in an elevated prompt.

Start cmd.exe as normal (click start/type cmd and choose cmd.exe with just the left click) and then do subst and you should see your Q. Then you can delete it with subst q: /d.

If you didn't create the drive-letter with subst it is possible it is created by another program using the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices. If your drive-letter is available for all users on this system it can be in there. (You will need a restart after changing it.) Although in my setup (Win7 ultimate) it was still visible by subst but it could not change/delete it (but perhaps it's no longer visible in Win8).


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nope, that's probably not a root cause, I've turned on full UAC, now my command prompt is started normally and subst returns nothing, see: – skroslak Sep 15 '13 at 17:00
And you can access Q and you verified it is a sub-directory on your C-drive? (probably yes, according to the drivespace in your first screen-shot) – Rik Sep 15 '13 at 17:18
yes, I can access Q: (regardless UAC) and the content changes are of course reflected to the real folder - C:\portableDrive – skroslak Sep 15 '13 at 17:36
Can you remember doing the subst in the first place? If not it could be created by another program in a registry key. I updated my answer for this. – Rik Sep 15 '13 at 18:08
For further troubleshooting (if it's not the reg key): if you create or login as another user is the drive still there? Then it's not made with subst. Also i take it it will survives a full reboot. (Normal subst does not survive a reboot (unless it's executed on startup somewhere). – Rik Sep 15 '13 at 21:45

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