The Interface not registered, Error 0x80040155 in Outlook, Excel, and other Office applications can occur because of various issues. Here are some quick fixes that will help you resolve this issue successfully.
Fix 0x80040155 Interface not registered error in Outlook, Excel, etc.
These suggestions will help you fix the Interface not registered error in Outlook, Excel, etc.
- Repair or Reset Microsoft Office
- Reinstall Microsoft Office using default settings
- Troubleshoot with Office Add-ins
- Register Ole32.dll
Make sure to use an admin account.
1] Repair or Reset Microsoft Office
The 0x80040155 error can occur due to corrupted or missing system files. Hence, repairing or resetting your Microsoft Office application will help you repair the missing or damaged files.
- First, go to Windows Search, type Control Panel, and launch it.
- From the Control Panel, go to Programs > Programs and Features.
- Over here, search for Microsoft Office, select it, and click on Change.
- Select Online Repair and repair your Office apps.
- Once done, check if you are still getting the same error.
2] Reinstall Microsoft Office using default settings
Reinstalling Microsoft Office will help you download a fresh copy of the software and ensure no missing or corrupted files. Also, there are no bugs that might be causing the issue.
- Press Windows Key + I to launch Settings.
- Go to Apps > Installed Apps.
- Search for Microsoft Office, click the three dots icon, and select Uninstall.
- Once done, go to Office.com, download the Microsoft Office installer, and run it.
- Finally, check if you still encounter the same 0x80040155 error code after installing.
3] Troubleshoot with Office Add-ins
Sometimes, office add-ins can cause errors like 0x80040155 Interface not registered. To fix this, try disabling or enabling the add-ins and see if it helps.
- Launch Microsoft Word.
- Go to File > Options and click on Add-ins.
- At the bottom of the Manage dropdown menu, select COM Add-ins and select Go.
- You first need to disable all the add-ons and then check if the issue is still there.
- If it works fine, enable the add-ins individually and check if the issue persists. If it reappears, you will know what caused it.
4] Register Ole32.dll
Start by ensuring that the Ole32.dll file is in the %windir%System32 folder and registered correctly in the Windows registry. If you don’t have the file, download it from another PC, place it in the respective folder, and then register it.
To register the DLL file, follow these steps:
- Press Windows Key + X and go to Windows Terminal (Admin).
- Next, if you are using 32bit Windows, then run the following command:
regsvr32.exe %windir%\System32\Ole32.dll
- If you are using 64-bit Windows, then run the following command:
%systemroot%\SysWoW64\regsvr32.exe %windir%\SysWoW64\Ole32.dll
- Then, from the RegSvr32 dialog box, click OK.
I hope the post helps.
How do I fix Excel activation?
You can quickly fix the Excel activation issue by signing in with your Microsoft account. However, you must have an Office 365 subscription or purchase a Microsoft Excel Subscription. If you face errors while verifying your license, go to File > Account > Update Options and select Update Now to update Excel.
What does “interface not registered” mean?
“Interface not registered” typically means an issue with the Outlook installation’s Common Object Model (COM) interface. The version reference for the TypeLib entry set by Outlook may be incorrect or point to a non-existent location. You can try re-registering DLL files or reinstalling Outlook to fix this error.
