Fix COMADMIN_E_KEYMISSING 0X80110403 Error

You see COMADMIN_E_KEYMISSING (0X80110403) when you open Component Services (dcomcnfg.exe), expand the COM+ Applications folder, and try to view or configure a specific COM+ application. The error message reads "The object was not found in the catalog". This happens most often after uninstalling a third-party application that installed its own COM+ components, or after a Windows update that broke the COM+ registration for a system component like MSDTC or IIS.

The root cause is straightforward: the COM+ catalog keeps a list of all registered components in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\COM3. When a component is removed incorrectly, its entry stays in the catalog but points to a registry key that no longer exists. The catalog can't find the component's CLSID or AppID, so it throws the "key missing" error.

Here's the fix. Start with the simple stuff — re-registering the core COM+ DLLs. If that doesn't cut it, we'll clean up the catalog manually.

Close Component Services — Don't leave it running. The COM+ catalog locks files while it's open.
Open an elevated Command Prompt — Press Windows Key + X, then click Terminal (Admin) or Command Prompt (Admin).
Re-register COM+ core DLLs — Run these four commands one at a time. You won't see a confirmation message until the last one.
```
regsvr32 /s /n /i:U clbcatq.dll
regsvr32 /s comadmin.dll
regsvr32 /s comsvcs.dll
regsvr32 /s colbact.dll
```
After each command, you should see a pop-up that says "DllRegisterServer in [dllname] succeeded". If you get an error instead, note the error code — it means a system file is corrupted on your PC.
Restart the COM+ System Application — Open Services (Windows Key + R, type services.msc, enter). Scroll to COM+ System Application, right-click it, then click Restart. This forces Windows to reload the catalog.
Open Component Services again — Press Windows Key + R, type dcomcnfg.exe, press Enter. Expand Component Services → Computers → My Computer → COM+ Applications. The error should be gone now.

If the error still shows up in step 5, the corrupted entry is likely in a third-party COM+ application. You need to remove it by hand.

Identify the broken application — In Component Services, right-click the application that gives you the error (you'll see it listed with a red X or a missing icon). Click Properties. On the General tab, note the Application ID (a GUID like {12345678-1234-1234-1234-123456789abc}). Close the properties window.
Remove the broken application — Right-click the same application and choose Delete. Confirm the deletion. The application and its catalog entry are now gone.
Re-add the application — If the application is needed (like a system component), right-click COM+ Applications, choose New → Application. Select Create an empty application, give it the same name, and follow the wizard. For system components like MSDTC, run msdtc -install from an elevated command prompt instead.

Still failing?

If the error persists after all this, the registry itself might be damaged. Run sfc /scannow from an elevated command prompt — this checks and repairs protected system files. After the scan finishes (it takes about 15 minutes), restart your PC and repeat steps 1-5.

If SFC finds nothing, the final option is a Windows repair install using the Windows 10/11 Media Creation Tool. It reinstalls Windows without deleting your files. I've seen this fix COM+ catalog issues that nothing else could touch.