Upgrade from Win 8.1 to Win 10 Pro, then the following error shows when reboot. Windows 10 Critical Error:
Start Menu and Cortana aren't working. We'll try to fix it the next time you sign in.When I sign out and sign in again, nothing changes! How to fix this?
1. Restart your computer
2. Double click on control panel,
3. View by: small icons
4. Click Administrative tools
5. Double-click Services
6. Type U to quick find User Managers
7. Double click User Manager; > select Automatic from Start type
8. Click Apply first, and then OK
9. Reboot.