Moderate Severity
0x80040154 Error: Class Not Registered
Error 0x80040154 indicates a COM class is not registered in the Windows registry. This means an application is trying to use a COM component that either was never registered, has been unregistered, or has a broken registration. Common with applications that rely on ActiveX controls or COM libraries.
Common Causes
- COM component DLL not registered
- Application not properly installed
- 64-bit/32-bit COM registration mismatch
- Corrupted application installation
- Windows component store damage
- Uninstalled program left broken references
- Registry cleanup tool removed COM entries
Symptoms
- Application fails to start with class not registered
- Specific application features do not work
- Internet Explorer or Edge features break
- Windows shell extensions stop working
- Script errors referencing COM objects
How to Fix 0x80040154
- Re-register the COM DLL using regsvr32
- Repair or reinstall the affected application
- Register both 32-bit and 64-bit versions of the DLL
- Run SFC /scannow to repair system components
- Check if the DLL file exists in the expected location
- Restore registry entries from backup
- Reinstall the application that owns the COM component
What Is Error
Error code 0x80040154 is a Windows HRESULT error code that translates to "Class Not Registered". HRESULT codes are hexadecimal values used throughout the Windows operating system to indicate specific error conditions. When you see this error, it means Windows or an application encountered the condition described above and could not continue the operation.
The error code format breaks down as follows: the leading 0x8 indicates a failure, the next digits identify the facility (the Windows subsystem that generated the error), and the remaining digits specify the exact error condition.
How Serious Is
Error 0x80040154 is not typically an emergency, but it will prevent certain operations from completing. You can continue using your computer for other tasks while troubleshooting. Work through the fixes below in order, starting with the simplest solutions.