“The Local Device Name Is Already in Use”: How to Fix Mapped Drives

Applies to: Windows 11 and Windows 10, mapped network drives in File Explorer, net use, logon scripts and VPN connections.

What the error means

You’ll see “The local device name is already in use” in File Explorer when you open or map a network drive, or “System error 85 has occurred. The local device name is already in use.” in Command Prompt.

A “local device name” is a drive letter such as Z:. Windows can only connect one thing to each letter. The error means the letter you chose is still claimed by something else: a mapping that didn’t disconnect cleanly, a mapping saved from an earlier session, or a local drive.

Fix 1: Delete the old mapping and map it again

This fixes most cases. Press Win, type cmd and open Command Prompt (a normal window, not as administrator, because mapped drives belong to your own sign-in). Then run:

net use

This lists every mapped letter, its network path and its status (OK, Disconnected or Unavailable). Delete the one that’s causing the error, then map it again:

net use Z: /delete
net use Z: \\SERVER\Share /persistent:yes

Replace Z: and \\SERVER\Share with your own letter and path. If it asks for a username and password, enter the account that has access to the share. To clear every mapping at once and start fresh, use net use * /delete and answer Y.

Prefer File Explorer? Right-click the drive under This PC, choose Disconnect, then use Map network drive to add it back.

Fix 2: Use a different drive letter

If you just need access now, map the share to a letter nothing else uses, such as Y: or W:. In File Explorer, select This PC > Map network drive and pick a free letter from the list, or run net use Y: \\SERVER\Share.

This is also the right fix when the same letter is mapped by a company script, because a script will keep re-mapping it.

Fix 3: Free the letter in Disk Management

Sometimes a local device has taken the letter: a USB stick, card reader, DVD drive or a hidden partition. Then no mapping can use it.

1. Right-click the Start button and choose Disk Management.
2. Look for any drive using the letter you want.
3. If it’s a removable drive or card reader you can live without on that letter, right-click it, choose Change Drive Letter and Paths, select Change, and give it a letter near the start of the alphabet, such as E:.

Don’t change the letter of C: or of a drive that installed programs live on. Map the network share to a different letter instead (Fix 2).

Fix 4: Clear saved credentials

Old saved passwords for the server can leave a half-made connection that holds on to the letter.

1. Open Control Panel > Credential Manager > Windows Credentials.
2. Find entries for the server name or IP address, expand them and select Remove.
3. Restart, then map the drive again (Fix 1) and enter the current username and password.

Windows only allows one set of credentials per server at a time. If you need two shares on the same server with different accounts, connect to one of them by IP address and the other by name.

Fix 5: Restart the Workstation service

The Workstation service handles all your network drive connections. Restarting it drops every connection and clears stuck ones. Save any files open from network drives first, then open Command Prompt as administrator and run:

net stop workstation /y
net start workstation

Restarting the PC does the same thing. Then map the drive again.

Fix 6: VPN and logon-script mappings

If you work from home, Windows often tries to reconnect mapped drives at sign-in, before your VPN is connected. The mapping fails but still claims the letter, so the next attempt shows this error.

1. Connect to the VPN first.
2. Run net use and delete any mapping marked Unavailable or Disconnected.
3. Map the drive again, or run your company’s mapping shortcut or script again.

At work, drives are often mapped by a logon script or Group Policy. If two scripts map different shares to the same letter, you’ll get this error every time you sign in. Ask your IT team to check the drive mappings for your account.

Fix 7: Remove a stuck mapping from the registry

If the letter still won’t map and net use doesn’t list it, a saved (persistent) mapping may be left in your profile. Back up the key before you change anything.

1. Press Win + R, type regedit and press Enter.
2. Go to HKEY_CURRENT_USER\Network. Each subkey is named after a mapped drive letter.
3. Right-click the subkey for the problem letter (for example Z), choose Export to save a backup, then choose Delete.
4. Sign out and back in, then map the drive again.

Only delete the subkey for the letter that’s causing trouble. If you can’t reach the share at all, even by its path, the problem is the connection rather than the letter. Our guide to error 0x80070035 (network path not found) covers that.

Frequently asked questions

What is system error 85?

System error 85 is the Command Prompt version of “The local device name is already in use”. It means the drive letter you used with net use is already taken.

Why does the error come back every time I restart?

Something is re-creating the mapping at sign-in: a saved (persistent) mapping, a logon script or Group Policy. Delete the saved mapping (Fixes 1 and 7), or if it’s a company script, ask IT to change the letter it uses.

Will deleting a mapped drive delete my files?

No. Disconnecting a mapped drive only removes the shortcut letter on your PC. The files stay on the server or NAS, and you can map the drive again at any time.

Does this error happen with OneDrive or SharePoint?

It can, when a SharePoint library is mapped as a drive letter. The same fixes apply, but Microsoft recommends syncing SharePoint libraries with OneDrive instead of mapping them, which avoids the problem.