Fix WMI Already Enabled Error 0XC0000303 in 5 Minutes

Quick Answer

Run winmgmt /resetrepository as admin, then restart the Windows Management Instrumentation service. That fixes 0XC0000303 in most cases.

Why You're Seeing Error 0XC0000303

Error 0XC0000303 maps to STATUS_WMI_ALREADY_ENABLED. It pops up when a WMI event subscription, event filter, or performance counter collection gets registered twice — once by the system, once by a monitoring tool or script. I've seen this most often on Windows Server 2016 and 2019 boxes running SolarWinds or PRTG, but also on Windows 10/11 machines with third-party antivirus that hooks into WMI.

The real trigger is usually a corrupted WMI repository. When the repository gets out of sync, it loses track of what's already registered. So when software tries to register the same event again, WMI says "nope, that's already enabled" and throws this hex error. Don't bother hunting through logs — the error text itself tells you everything: the collection or event is already enabled.

Fix It in 6 Steps

These steps assume you're on Windows 10, Windows 11, or Windows Server 2016/2019/2022. You'll need admin rights.

1. Open Command Prompt as Administrator — Click Start, type cmd, right-click Command Prompt, select Run as administrator. Click Yes when UAC asks.
2. Stop the WMI service — In the command prompt, type net stop winmgmt and press Enter. You'll see a message like "The Windows Management Instrumentation service is stopping..." Wait for it to say "stopped successfully."
3. Reset the WMI repository — Type winmgmt /resetrepository and press Enter. This deletes the current WMI database and rebuilds it from scratch. It wipes all custom WMI settings — so if you've got custom MOF files or specific event filters, you'll need to reapply them after. You'll see "The WMI repository is being reset." If it succeeds, it says "The operation completed successfully." If it fails, skip to Alternative Fixes below.
4. Restart the WMI service — Type net start winmgmt and press Enter. You'll see "The Windows Management Instrumentation service is starting..." then "started successfully."
5. Reboot the machine — This isn't always needed, but I recommend it. Some WMI providers load during boot, and a clean start flushes any stale state. Type shutdown /r /t 0 and press Enter.
6. Test — After reboot, open a new Command Prompt as admin and run wbemtest. Click Connect, leave the namespace as root\default, click Connect again. If you don't get an error, WMI is working. Then try whatever monitoring tool or script originally gave you error 0XC0000303 — it should work now.

Alternative Fixes (If the Main One Fails)

If winmgmt /resetrepository failed with an access denied or corrupted repository error, here's the backup plan:

Alternative 1: Force Re-register WMI Components

1. Open Command Prompt as admin.
2. Type these commands one at a time, pressing Enter after each:

   cd /d %windir%\system32\wbem
   for /f %s in ('dir /b *.dll') do regsvr32 /s %s
   for /f %s in ('dir /b *.exe') do %s /regserver
   mofcomp.exe -n:root\default wbemcons.mof
   mofcomp.exe -n:root\default wbemcore.mof
   winmgmt /resyncperf

3. Restart the WMI service: net stop winmgmt then net start winmgmt.
4. Reboot.

Alternative 2: Delete the Repository Manually

Only do this if the reset command hangs. It's a bit brute force.

1. In Command Prompt as admin, stop WMI: net stop winmgmt.
2. Delete the repository folder: rd /s /q C:\Windows\System32\wbem\Repository. Yes, it's safe — WMI re-creates it on next start.
3. Restart WMI: net start winmgmt.
4. Reboot.

Alternative 3: Check for Competing Monitoring Software

Sometimes the error isn't a corrupt repository — it's two tools fighting over the same WMI event. Open Event Viewer (eventvwr.msc), go to Applications and Services Logs > Microsoft > Windows > WMI-Activity > Operational. Look for Event ID 5601 or 5602 around the time the error happened. If you see a specific provider name, Google it. Uninstall one of the conflicting tools.

Prevention Tip

Stop your monitoring tools from hammering WMI with duplicate event registrations. If you use PowerShell scripts to create permanent WMI event filters (like Register-CimIndicationEvent), always check if the filter already exists first. Use Get-WmiObject -Namespace root\subscription -Class __EventFilter to list current filters. Also, keep Windows Update current — Microsoft patched a known WMI corruption bug in KB5006670 for Windows 10 version 21H1. Without that patch, the repository gets corrupted more easily, and you'll see 0XC0000303 more often.