Fix 0X00000846 (NERR_DuplicateShare): Share name already exists

Quick answer (skip the rest if you know what you're doing)

Use net share ShareName /delete in an admin command prompt, then re-create the share with a different name. If that fails, reboot the machine to clear SMB cache.

Why this happens

0X00000846 maps to NERR_DuplicateShare — Windows error code 2118. The share name you're trying to create already exists somewhere in the SMB namespace. What's actually happening here is the system sees the name as taken even if you can't see it in File Explorer or net share.

Common real-world triggers:

• You deleted a share via the GUI but Windows didn't remove it from the registry cache.
• A hidden administrative share (like C$) conflicts with a manual share you're adding.
• A stale connection from a previous session is still registered (especially after a network drop).
• You're on Windows Server and a DFS (Distributed File System) target with the same name exists elsewhere.

The reason step 3 works is that a full reboot forces the SMB server service to flush all stale share entries. Don't skip it if the quick delete doesn't work.

Fix steps (the exact order that works)

1. Open admin command prompt. Press Win+X, choose Terminal (Admin) or cmd (Admin).
2. List all shares, including hidden ones:
   net share
   Look for the share name you're trying to create. If you see it, proceed to delete it.
3. Delete the existing share:
   net share YourShareName /delete
   Replace YourShareName with the actual name. If you get 'access denied', you're not running as admin.
4. Recreate the share with the same name:
   net share YourShareName=C:\Path\To\Folder /grant:Everyone,Full
   Adjust permissions as needed.
5. If step 3 fails with 'The file or directory is not a reparse point':
   That means the share is a special mount point or symbolic link. Use this instead:
   net share YourShareName="C:\Path\To\Folder" /remark:"My share"
   Quotes fix parsing issues with paths containing spaces.
6. Still failing? Reboot the machine. After restart, repeat steps 2–4. The reboot flushes the SMB server's internal share table.

Alternative fixes if the main one doesn't work

• Use PowerShell instead of net share:
  Remove-SmbShare -Name YourShareName -Force
  Then New-SmbShare -Name YourShareName -Path C:\Path\To\Folder -FullAccess Everyone
  PowerShell sometimes has more granular control.
• Check for hidden shares in the Registry:
  Open regedit and go to HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Shares. Here you'll see all registered shares including those not visible in net share. Delete the key under that path that matches your share name. Be careful — deleting system shares (ending with $) can break things. Only delete your custom share.
• Restart the Server service:
  net stop LanmanServer && net start LanmanServer
  This stops and restarts the SMB server. Any shares that are 'stuck' in memory get cleared. Do this only if no one is actively using shares on that machine.

Prevention tip

Before creating a share, always check for existing ones with net share | findstr /i "YourShareName". If you're scripting share creation, wrap it in a check like this:

net share | findstr /i "MyShare" >nul 2>&1
if %errorlevel% equ 0 (
    echo Share already exists, skipping creation
) else (
    net share MyShare=C:\Folder /grant:Everyone,Full
)

Also avoid using share names that match system administrative shares (ADMIN$, C$, IPC$). Windows won't block them, but it can confuse tools and cause weird conflicts.

If you see 0X00000846 on a machine that's had shares for years, it's almost always from a botched uninstall or a registry cleaner that only half-removed entries. Stick to net share or PowerShell to clean it up — avoid third-party tools for this.