The error “local device name is already in use” means that the drive letter or network path you tried to map is already taken by another connection on your computer, or the network resource you are trying to reach is already connected under a different name. You can usually fix it in under a minute by disconnecting the old mapping or changing the drive letter, and this article shows you exactly how.
What Does This Error Actually Mean?
When you map a network drive, Windows (and other operating systems) assigns a drive letter like Z: to a shared folder on another computer. The error “local device name is already in use” appears when the drive letter you chose is already assigned to something else, or when the network share you are trying to connect to is already mapped under a different drive letter. The system sees a conflict between what you want and what is already set up.
It is not a sign of a broken network or a virus. It is simply Windows telling you that the name or letter you are trying to use is taken. The same message can appear when you try to use the net use command in the command prompt, or when you try to reconnect a mapped drive that is still active from a previous session.
Common Causes of the Conflict
- Duplicate drive letter: You already have a drive mapped to
Z:and you try to map another share toZ:. - Same share, different letter: The same network folder is already mapped to
Y:, and you try to map it again toX:. - Stale connection: A previous mapping is still active in the background, even though you do not see it in File Explorer.
- Persistent mapping: The drive is set to reconnect at sign-in, but the network share is unavailable, causing a conflict when you try to map it manually.
- Multiple user sessions: If you are logged in as a different user, that user may have the same drive letter mapped.
How to Fix It on Windows
Here are the steps to resolve the error on Windows 10 and Windows 11. Try them in order, as the first one usually works.
- Disconnect the existing mapping: Open File Explorer, right-click on the mapped drive that uses the same letter, and select “Disconnect.” If you do not see it, open Command Prompt and type
net useto list all mappings. Then typenet use Z: /delete(replaceZ:with the letter that is in use). - Change the drive letter: If you cannot disconnect the old mapping, simply map the new share to a different letter. In File Explorer, right-click “This PC” and choose “Map network drive.” Pick an unused letter like
M:orN:. - Remove persistent mappings: If the drive reconnects every time you restart, run
net use Z: /delete /yin Command Prompt. This removes the mapping and stops it from reconnecting. - Check for hidden connections: Sometimes a mapping is not visible in File Explorer. Open Command Prompt and type
net useto see all active connections. If you see the same share under a different letter, disconnect it withnet use * /delete(this deletes all mappings). - Restart the Workstation service: If the above fails, restart the “Workstation” service. Press
Win + R, typeservices.msc, find “Workstation,” right-click and select “Restart.”
How to Fix It on macOS and Linux
On macOS, the error is less common but can appear when you try to mount a network share that is already mounted. To fix it, open Finder, press Cmd + K to connect to a server, and if the share is already mounted, you will see it in the sidebar. Right-click and select “Eject.” Then reconnect. If you are using the command line, mount will show existing mounts, and umount /Volumes/ShareName will unmount it.
On Linux, the error usually appears when you try to mount a network share to a mount point that is already in use. Check with mount | grep /mnt/share and unmount with umount /mnt/share. If the mount point is a directory with existing files, you may need to use a different mount point.
How to Prevent It From Happening Again
- Use a consistent drive letter: Always map the same share to the same letter. This avoids conflicts.
- Uncheck “Reconnect at sign-in” if you do not need the drive to be permanent.
- Use the full UNC path instead of a drive letter when possible. For example, type
\\server\sharedirectly in File Explorer’s address bar. This bypasses drive letter conflicts entirely. - Check for orphaned mappings: Periodically run
net useand delete any mappings you no longer need.
When to Use a Different Approach
If the error persists after trying all the steps, the issue may not be a simple drive letter conflict. It could be that the network share is on a server that has reached its connection limit. Windows has a default limit of 20 concurrent connections for each share on a workstation. If you are connecting to a Windows Home or Pro machine, try disconnecting other users from that share. Alternatively, the server may be offline or unreachable. Test with ping server-name and try to access the share by IP address instead of hostname.
Another workaround is to use the IP address directly: \\192.168.1.10\share instead of \\server-name\share. This can bypass DNS or NetBIOS name resolution issues that sometimes cause the error.
Frequently Asked Questions
What does “local device name is already in use” mean?
It means the drive letter or network path you are trying to use is already assigned to another mapping. The system cannot have two different network shares using the same local drive letter.
How do I find which drive letter is already in use?
Open Command Prompt and type net use. It lists all active mappings and their drive letters. You can also open File Explorer and look at “This PC” to see which letters are occupied.
Can I map a network drive to a folder instead of a drive letter?
Yes. Instead of using a drive letter, you can create a shortcut to the UNC path (e.g., \\server\share) and place it on your desktop. This avoids the drive letter conflict entirely.
Why does the error appear after I restart my computer?
If the drive is set to “Reconnect at sign-in,” Windows tries to map it automatically. If the network share is not available at that moment, the mapping may fail, and when you try to map it manually later, the system still sees the old (failed) mapping as active. Disconnect it with net use and remap.
Is this error a security risk?
No. It is a configuration conflict, not a security issue. It does not indicate a breach or a malware infection. It is simply a network resource naming problem.
What if I still get the error after deleting all mappings?
If net use * /delete does not help, restart the computer. This clears all temporary network connections. If it still fails, check if the server itself has reached its connection limit, or try connecting via the IP address instead of the hostname.