ErrorFindly
0x80070055SystemLow

Error 0x80070055 — Already Assigned (ERROR_ALREADY_ASSIGNED) | Windows System Error Fix

Windows 11Windows 10Windows Server 2022

What Does 0x80070055 Mean?

The local device name (drive letter) is already in use and cannot be assigned to a network resource.

Real-World Causes

  1. 1Attempting to map a network drive to a letter already used by a local or mapped drive
  2. 2Login script trying to remap an already-mapped drive letter
  3. 3Drive letter conflict between local disk and network mapping

Symptoms

  • ⚠'net use' command fails with 'already assigned' error
  • ⚠Cannot map network drive to desired letter
  • ⚠Login scripts fail partially
  • ⚠Drive mapping dialog shows error

DIY Fix

Beginner-friendly steps you can try at home

  1. 1Choose a different drive letter for the network mapping
  2. 2Disconnect the existing mapping first: 'net use X: /delete'
  3. 3Check existing mappings with 'net use' command
  4. 4Use Disk Management to change a local drive's letter

Advanced Fix

For experienced users and IT professionals

  1. 1Clean up stale mappings in registry: HKCU\Network
  2. 2Use 'net use * \\server\share' to auto-assign next available letter

Frequently Asked Questions

How do I see all drive letter assignments?
Open Disk Management (diskmgmt.msc) to see local drive assignments, and run 'net use' in Command Prompt to see network drive mappings. Together these show all assigned drive letters.

Related Error Codes

0x80070035Bad Network Path (ERROR_BAD_NETPATH)0x8007000FInvalid Drive (ERROR_INVALID_DRIVE)

About the Author

Windows Troubleshooting Team

Verified against official Microsoft documentation and real-world diagnostic data. Error behavior confirmed across Windows 10, Windows 11, and Windows Server.