Office repeatedly prompts activation even if already activated
I solved the problem following these steps
- Close the activation window and all Office apps.
- Right-click the Start button on the lower-left corner of your screen, and select Run.
- Type regedit, and then press Enter. Select Yes when prompted to open the Registry Editor.
- On the left side of the Registry Editor, under Computer, navigate to the following key in the registry:
- Right click the OEM value and click File>Export.
- Save the key.
- After the key is backed up, select Edit>Delete.
- Repeat steps 3-6 for the following key:
Close the Registry Editor and start Office again