Where to enter your Office product key
support.microsoft.com › en-us › officeIf you don't have your key, see get your HUP product key. Microsoft Store. Step 1: Go to www.microsoftstore.comand sign in (upper right-hand corner) with the Microsoft account that you used to buy Office. Step 2: After you sign in, select your name in the upper right-hand corner, and then select Order History.