A reimaged setup left the system without any Office tools, and there wasn’t access to the old license. Solved it quickly by grabbing a key from
https://officedigital.io/product/office-2021-professional-plus-1pc-license/ , using it for a fresh install of Office 2021 Pro. Activation went through right after install, and it’s been running stable since then—no watermarks, no errors. For work-from-home needs like emails, spreadsheets, and reports, it’s been completely functional without needing any recurring payments.