Cannot write to registry key HKCU\Software\Classes\CLSID



When installing the Office Timeline add-in or activating your license, you receive an error message related to HKCU\Software\Classes\CLSID.

This error is caused by one of these two reasons:

  • Your user account does not have sufficient registry permissions to allow Office Timeline to correctly register itself on your computer.

  • An antivirus application is preventing PowerPoint and Office Timeline from properly registering the add-in.


This problem can be solved by granting the correct permissions to your user account for the HKCU\Software\Classes\CLSID registry key or by creating an exception for PowerPoint in your antivirus application.

Steps for Granting Registry Permissions

  1. Uninstall Office Timeline from your computer.  In Windows, navigate to the Control Panel > Programs and Features, select Office Timeline from the list and click Uninstall.

  2. Press the Windows key on your keyboard to open windows search and type Regedit to open the Registry Editor.

  3. Navigate to HKEY_CURRENT_USER > Software > Classes > CLSID (HKCU\Software\Classes\CLSID).

  4. Right-click on the CLSID folder and select Permissions.

  5. In the permissions dialog, select the Office Timeline user’s name.  If the user's name is not listed, click Add... to add the user.

  6. In the Permissions for CLSID window, make sure the user has Full Control and Read permissions checked and click OK.

  7. Download the most current version of Office Timeline from

  8. Re-install Office Timeline.

  9. Once Office Timeline has re-installed, click on the Office Timeline tab in PowerPoint and click on the Upgrade button to re-activate your license using your product key.  See How to Activate Office Timeline

Steps for allowing your antivirus application to grant PowerPoint the ability to read and write to the registry and the local file system.

Because every antivirus application is different, you will have to contact your IT department or do a bit of detective work on your own.  Here is an example for how to grant exception to PowerPoint through Appguard's Tech Fortress:

  1. Open the Tech Fortress application and click Customize...

  2. Uncheck Microsoft PowerPoint from the list of Guarded Apps.

  3. Reinstall Office Timeline or try activating your license again.