0x80040154SystemMedium

Error 0x80040154 — Class Not Registered (REGDB_E_CLASSNOTREG) | Windows System Error Fix

Windows 11Windows 10Windows Server 2022Windows 8.1

What Does 0x80040154 Mean?

The specified COM class is not registered in the system registry.

Real-World Causes

1COM component was not properly registered during installation
2DLL containing the COM class was deleted or moved
332-bit COM component accessed from 64-bit process or vice versa
4Incomplete application uninstall left broken references

Symptoms

⚠Application feature fails with 'class not registered' error
⚠Windows Explorer or shell features malfunction
⚠Script automation fails with REGDB_E_CLASSNOTREG
⚠Control Panel applets fail to open

DIY Fix

Beginner-friendly steps you can try at home

1Reinstall the application that provides the COM component
2Re-register the DLL: 'regsvr32 component.dll' from elevated Command Prompt
3For 32-bit components on 64-bit system: use 'C:\Windows\SysWOW64\regsvr32.exe component.dll'
4Run 'sfc /scannow' for system COM components

Advanced Fix

For experienced users and IT professionals

1Find the CLSID in the error details and search HKCR\CLSID for the registration
2Use OleView.exe to inspect COM class registrations
3For architecture mismatches, ensure 32-bit apps use 32-bit COM and 64-bit use 64-bit

Frequently Asked Questions

What does 'class not registered' mean?

Windows maintains a registry of COM classes (software components). Each class has a unique ID (CLSID). When an application requests a COM class, Windows looks it up in the registry. If the entry is missing or points to a non-existent DLL, you get this error.

Related Error Codes

0x80040111Class Not Available (CLASS_E_CLASSNOTAVAILABLE)0x80040150Read Registry Database (REGDB_E_READREGDB)

About the Author

Windows Troubleshooting Team

Verified against official Microsoft documentation and real-world diagnostic data. Error behavior confirmed across Windows 10, Windows 11, and Windows Server.