How to fix Error 418 on Windows 11

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Why This Error Happens

Error 418 (“The specified storage reserve already exists”) occurs when Windows attempts to create a new reserved storage partition or Storage Spaces pool, but a matching entry already exists in the Virtual Disk Service (VDS) configuration database. This typically happens after a failed or interrupted update, a duplicate storage pool creation attempt via PowerShell, or leftover metadata from a previous Storage Spaces configuration that wasn’t properly cleaned up. It can also occur if two processes (e.g., Windows Update and a manual script) try to reserve the same disk space simultaneously.

Step-by-Step Resolution Guide

  1. Check existing storage reserves via PowerShell
    Open PowerShell as Administrator and run:
   Get-StoragePool | Select FriendlyName, OperationalStatus

Identify if a pool with a conflicting name or GUID already exists.

  1. Remove the conflicting storage reserve
    If a duplicate or orphaned reserve is found, remove it:
   Get-StoragePool -FriendlyName "<PoolName>" | Remove-StoragePool -Confirm:$false

Replace <PoolName> with the name returned in Step 1.

  1. Clear residual VDS cache
    Navigate to C:\Windows\System32\drivers\ and restart the Virtual Disk service:
   net stop vds
   net start vds

This forces Windows to rebuild the storage configuration cache and clear stale reserve entries.

  1. Re-run DISM health checks
    Open an elevated Command Prompt and run:
   DISM /Online /Cleanup-Image /RestoreHealth

This repairs the underlying component store that may be causing Windows to misreport an existing reserve.

  1. Retry the original operation
    Attempt the original action (e.g., creating the storage pool, resizing reserved storage, or completing the Windows Update) that triggered Error 418.

Alternative or Verification Steps

  • After completing the steps, run Get-StoragePool again to confirm no duplicate entries remain, and verify the intended storage reserve now appears correctly under Settings > System > Storage > Advanced Storage Settings.
  • If the error persists, boot into Safe Mode and repeat Steps 2–4, as background services holding a lock on the VDS database can sometimes prevent proper removal in normal mode.