Office can't activate after Windows 11 upgrade - Office error code 0x80070005
Close all Office apps.
Right-click the Windows button in the lower left-hand corner of your screen and select Run.
In the Open box, type regedit, and select OK.
Select Yes when prompted to allow Registry Editor to make changes to your device.
In the Registry Editor, expand HKEY_USERS and select S-1-5-20.
- Right click on S-1-5-20 and click Permissions
- Scroll down and click on Users
- If the Full Control check box is empty tick it to enable it.
8. Try and open a Office Application, it should no longer prompt for an activation.