A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
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.
Win search for Word > Resulting shortcut > Rt click > Pin to task bar > start Word from that shortcut (hover mouse over the shortcut gives access to the 10 most recent docs)
Can you open excel itself or is the problem with a specific doc?