Dear @James Omukama,
Thank you for posting your question in the Microsoft Q&A forum. I understand you are trying to install 64‑bit Office, but you keep getting an error saying some 32‑bit parts are still on your computer (like Office16 Click‑to‑Run Extensibility Component).
To better assistance, could you please confirm following information:
- Is this a school/work computer or your personal PC?
- Which Windows version do you have (Windows 10 or 11)?
- How did you uninstall Office before (Control Panel, Settings, or a tool)?
- Do you still see Microsoft Office Click‑to‑Run in Services or Task Manager?
- Do you have admin rights on this PC?
In the meantime, I recommend some step below:
Option 1: Use Microsoft’s uninstall tool
- Go to: Uninstall Microsoft 365 or Office from a PC > Click Uninstall
- Click Open if you get a pop-up window indicating This site is trying to open Get Help.
- Follow the prompts on the remaining screens and when prompted, restart your computer.
- Select the steps for the version of Office you want to install or reinstall.
Option 2: If the error still shows after using the tool
Note: Please back up your registry first. Only do this if the uninstall tool fails.
- Remove leftover registry keys: Press Windows + R, type regedit, and press Enter. Navigate to: HKEY_CLASSES_ROOT\Installer\Products\ Look for keys mentioning Office16 Click-to-Run Extensibility Component and delete them.

- Clear identity cache: Go to: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities Delete all entries under Identities.
- Check for old Office folders: Delete any remaining folders: C:\Program Files (x86)\Microsoft Office C:\Program Files\Microsoft Office Also check %ProgramData%\Microsoft\Office and %AppData%\Microsoft\Office.
- Restart your PC.
Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.
I truly appreciate your patience and understanding. If you have any further questions or need further clarification, please feel free to reach out. I'm looking forward to hearing from you.
Thank you for your cooperation.
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