Fix STATUS_REDIRECTOR_NOT_STARTED 0xC00000FB (Network File Error)

This error means Windows tried to access a network file before the network redirector started. The fix is restarting the Workstation service – takes 2 minutes.

Quick Answer

Open Command Prompt as admin and run: net stop lanmanworkstation && net start lanmanworkstation. Then retry your network file. That's usually it.

What This Error Actually Means

You double-click a file on a network share and bam – error 0xC00000FB. It says "network software not started" which sounds like gibberish. What's really happening is the Workstation service – that's the piece of Windows that talks to other computers on your network – isn't running yet or crashed silently.

I saw this a lot with small biz clients who use a mix of old and new hardware. One guy had a server that took 5 minutes to boot, and users would log in too fast. Another case: a printer spooler update killed the Workstation service without warning. The error pops up when Windows boots but the service didn't start, or when a service dependency failed.

Fix Steps (Start Here)

Open Command Prompt as admin. Hit Win+R, type cmd, then press Ctrl+Shift+Enter.
Check if Workstation service is running: sc query lanmanworkstation. Look for STATE: 4 RUNNING.
If it's stopped or stuck: Run net start lanmanworkstation. If it fails, go to step 4.
Force restart both services: net stop lanmanworkstation && net start lanmanworkstation. Wait 10 seconds.
Test your network file. Try opening it again.

If That Didn't Work – Dig Deeper

Sometimes the Workstation service depends on other services that also aren't running. Common culprits:

NetBIOS Helper – run net start lmhosts
TCP/IP NetBIOS Helper – net start lmhosts same command
Server service – net start lanmanserver

I had a case where the user's antivirus blocked the redirector at boot. Disable it temporarily, restart the service, then re-enable. Or check Windows Firewall – make sure File and Printer Sharing is allowed.

Alternative Fixes If Main One Fails

Check the registry: Open regedit, go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation. Make sure Start value is 2 (automatic). If it's 4, the service is disabled.
Boot into Safe Mode with Networking. Then restart the service there. If it works, a third-party driver or program is blocking it.
Run SFC and DISM: sfc /scannow then dism /online /cleanup-image /restorehealth. Corrupted system files can break the redirector.
Last resort – reinstall network stack: Reset Winsock with netsh winsock reset catalog and restart.

Prevention Tip

Set the Workstation service to Automatic (Delayed Start) in services.msc. This gives other services time to boot first. Also, update your network drivers – old Realtek or Broadcom ones are notorious for delaying service startup. And if you use a laptop that goes to sleep often, have users restart it before trying network files – I've seen that trigger this error more than anything.

Pro tip for IT folks: Write a small batch file that checks and restarts the service, then schedule it with Task Scheduler at logon. Saved me countless remote support tickets.