I have recently ran into issues on Windows 10 with the App Store missing or unable to open, the calculator not working (how did MS mess that one up), and Office having activation issues. The first time seemed to be a fluke. After all, it was right after a factory reset. The second time was after a hardware repair with Windows cleanup and update. Seems like these things are new Windows features. Here are some steps I took to get things working again.

If you get error 0x80070005 in Office applications, you can try to fix the issue by updating the registry.

Note: Before updating the registry, kindly take backup of the registry:

For updating registry, kindly try to perform below steps:

1. Close all Office apps.
2. Right-click the Windows button in the lower left-hand corner of your screen and select Run.
3. In the Open box, type regedit, and select OK.
   

Select Yes when prompted to allow Registry Editor to make changes to your device.

1. In the Registry Editor, expand HKEY_USERS and select S-1-5-20.
2. Right-click S-1-5-20 and select Permissions.
3. Select Add.
4. Type the logged in user's name, select Check Names, and then select OK.
5. Select Advanced.
6. In Advanced Security Settings, on the Permissions tab, select the user you just added, and then select Edit.
7. Under Basic permissions, select Full Control, and then select OK.

This takes you back to Advanced Security Settings.

1. In Advanced Security Settings, on the Permissions tab, select NETWORK SERVICE, and then select Edit.
2. Under Basic permissions, select Full Control (if not already selected), and then select OK.

This takes you back to Advanced Security Settings.

1. In Advanced Security Settings, select the checkbox named Replace all child object permission entries with inheritable permission entries form this object and select OK.
2. Close Registry Editor and restart any Office app to try to identify the issue result in Outlook

Meanwhile, you can also try to run Office as administrator (Right click Word or Excel or Outlook, select Run as administrator) to see if it can help.

If the issue still persist, kindly try to fix the Office or Outlook related issue via SaRA tool. So, kindly try to download Sara Tool and sign in with your work or school account and select the Office or Outlook issue you want help with.

Here is the download link for SaRA tool: Download Microsoft Support and Recovery Assistant for Office 365.

For more information about the tool, see Automatically diagnose and fix Outlook issues.

Note: Uncheck the box to let the organization control the device and use the link to log in to the application only. This seems to bypass some additional checks.