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As can be seen in the screenshots below, a weird drive letter shows up under "Computer" which however is not mapped in the Disk Manager. I guess it is some kind of service that creates this drive. How can I find out, which service or program is responsible for it? How can I remove it?


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migrated from May 3 '12 at 9:02

This question came from our site for system and network administrators.

You'll probably get more useful eyes on this at SuperUser. – SmallClanger May 3 '12 at 8:27
Thank you, I'll try it there – Philipp F May 3 '12 at 8:32
Drive label is Hulk.... Dis you set it? – Remus Rigo Jun 23 '12 at 15:37

It might be related to Office Click-and-Run. This Microsoft KB article has more information:

Why do I have a "Q:" drive when I use Office Starter To-Go?

Office Starter To-Go uses the Office Click-to-Run technology that must use a virtual application drive. This virtual application drive is why you have the Q: drive.

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Thanks for the hint, but I have Office 2007, so I'm afraid it is not office... – Philipp F Jun 24 '12 at 17:26

Perhaps it's created using SUBST?


C:\Users\graeme>subst /?
Associates a path with a drive letter.

SUBST [drive1: [drive2:]path]
SUBST drive1: /D

  drive1:        Specifies a virtual drive to which you want to assign a path.
  [drive2:]path  Specifies a physical drive and path you want to assign to
                 a virtual drive.
  /D             Deletes a substituted (virtual) drive.

Type SUBST with no parameters to display a list of current virtual drives.

Example, make the local drive G: refer to C:\Users\Graeme\Desktop:

C:\Users\graeme>subst g: c:\users\graeme\desktop

Show existing:

G:\: => C:\users\graeme\Desktop

Unlike mapped drives, virtual drives created using SUBST do not persist between sessions, so it is typically used in a logon script if persistence is needed.

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I tried subst, but no mappings appear. It has to be some service I guess, I just don't know which one. Is there any way to get the creator of a virtual drive? – Philipp F May 3 '12 at 11:51
Both SUBST'd drives and mapped drives are only visible in the session they're created in, so if a service created it, it's unlikely you would see it in your session. – ThatGraemeGuy May 7 '12 at 8:27

If you are talking about the CD/DVD ROM, it is likely to be a virtual drive mounted from an ISO file. We had exactly the same problem and it turned out to be UltraISO and just went to Tools.Mount Virtual Drive and disabled it

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It's not a CD-ROM. I disabled all virtual CD drives in PowerISO. The Q-Drive is still there – Philipp F May 3 '12 at 11:51

Do you have APP-V (-aka SoftGrid) installed? Microsoft Application Virtualization mounts its ".SFT" file to drive Q: to run applications. The file it mounts would be located here: "C:\ProgramData\Microsoft\Application Virtualization Client\SoftGrid Client"

As others have said, typically it won't show up in Disk Management if its a mounted container file like an ISO, SFT, BIN, etc.

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Don't have it installed.. I'm still looking for a way to find the responsible program for any mapped drive letter... – Philipp F May 20 '12 at 14:56

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