A Microsoft file hosting and synchronization service.
Restart the PC, once fully loaded, repair Office,> Apps & Features>Select Office your version>Modify /Repair, once the repair completes re-test (Quick repair)
O365 when installed under a Win user admin account, and run from that admin account, auto logs in when the PC is started. There is no separate login for any component.
The OneDrive cloud icon, to the rt of your taskbar rt click > settings shows storage
O365 must be installed/run under a win user Admin account