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I try to map a network resource to my local device.

I receive the following error: The local device name is already in use.

I have the problem to find which purpose the device is used for. I try a command net use and do not see it in the list, therefore, it is not mapped to a network resource.

Does anybody know how to see the list of all used devices in Windows 7?

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net use is the typical way to check. I'm not sure why it would be claiming to be in use if it is not there. – Jeff F. Feb 1 '11 at 14:30
@Jeff: exactly, also not clear for me – Tim Feb 1 '11 at 14:34
@Tim silly question: Have you rebooted? Also have you ensured that no physical device is using that letter(in disk management) – Jeff F. Feb 1 '11 at 14:37
@Jeff: I use 2 physical disks that are partitioned into C:\ and V:\ correspondingly + 2 network resources that are mapped to W:\ and Z:\ as you see there is no I:\ among them. Why do I have to reboot? – Tim Feb 1 '11 at 14:42
@Tim reboots have been the universal MS fixer since 3.0 :) – Jeff F. Feb 1 '11 at 14:43

You need to remap the drive.


net use * /delete

Then remap it using net use again:

net use Z: \\server\share /user:username password
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thank you sir!! I had disconnected a device from the gui, but the device name was "already in use". – Stefanos Kalantzis Mar 15 '12 at 13:36
thanks dekyos, this helped me too – DextrousDave Aug 16 '13 at 14:25
Why do I have to do this? The drive died on me literally while moving a file. This is outrageous. – rr- Apr 5 '15 at 10:29

It happened to me when I woke the computer from overnight sleep. I started stopping service after service and it seems that "Computer Browser" was at fault in my case. Try:

net stop "Computer Browser"  
net start "Computer Browser"
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  1. Delete the key

  2. Log off and then log on.

If it still does not work, disconnect all mapped drives either from GUI or better from command line as in the previous post, delete the reg key above and then log off and log on

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The other options wouldn't help for me, but this fixed it. What happend was that for some strange reason, a CD drive appeared at D: (it's a virtual machine) which conflicted with my existing network mapping on D:. Removing this key and logging off/on showed the CD drive. – Pieter van Ginkel Apr 12 '14 at 6:15

One possibility that I just ran into is that you've added a device to your system that causes other "auto mapped" devices to bump up over the mapped drive.

Say you have M mapped to a network drive, but you add a new harddrive, that then causes all the removable drives (even though they don't have anything inserted into them) to bump up a letter (or two).

Now, suddenly, one of the removeable drives is mapped to M.

Your network drive can no longer be mapped to M, and when you try to remove the mapping, it'll give you a "Device already in use" error.

Open up "Storage/Disk management" and check ALL the drives for any mapping that might be on top of the drive you want to map.

If there, just remap that drive to something else.

Then you should be able to use NET USE to attach to your network drive properly.

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There's an outside chance the cause of this is that the share you're trying to reach doesn't exist or has been disabled.

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Yep. Think in my case the remote computer (a Mac) had gone into sleep mode or something. – Simon East Nov 11 '13 at 0:06

I ran into this today, on several windows 7 and linux clients mapping drives from a linux samba server. The problem turned out to be that my root drive on the server had run out of space. clearing up a few gigabytes and restarting the samba server fixed the problem.

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I was having the same issue on a Windows Server 2008 SBS while i was trying to connect to an old NAS.

After trying each of the suggestions i saw here, i wasn't able to fix this.

During troubleshooting i found out that the root of the issue could be one of the assigned server IP's.

Indeed that was. I went to NAS logs and i saw that it was adjusted to connect with the NAS admin username and password under a specific IP address which was assigned to the server instead of server's main IP address!

So for future reference, i would suggest to check if you are under multiple NICS on your machine. If so you might have to remap the network share from a particular location.

Also, don't forget to read the logs of each device carefully.

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We had a Windows 7 laptop user whose printer was being mapped as the drive in question. But it wasn't showing up in Start->Computer and it wouldn't show up when listing with NET USE. However, if you went to Disk Management there was a removable media disk listed with no displayed drive letter that was mapped as the drive letter in question. If you right-clicked it, it would display EPSON in the properties.

We changed the drive letter to something that was not being used in Disk Management.

I asked my boss why a printer would map a drive, and he said it was so that the printer itself would deliver the drivers instead of Windows having to download them; but it assigns a drive letter without notifying some other Windows components apparently.

The errors that we got for it were Event ID 4098 with error code 0x80070055 in the application logs and when trying to map the drive letter with NET USE, Error 85 The local device name is already in use.

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I had this problem, here is a possible solution, make sure your sharing server has space left on the OS or root drive or "/".

I run a samba server on linux and the root drive was full. If samba can't create logs it crash and from the windows side it fails with the error "local device name is already in use" for some obscure reason.

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