You do not need to enter the product key into the apps themselves. Activation happens via your login. Open any Office app (like Word or Excel).

In the window, enter the email and password you used in Step 1.

Once validated, your subscription is officially active and tied to your account. 2. Download the Installer

: Open the downloaded .exe file. Select Yes when the User Account Control prompt appears. The installer will run in the background; stay online until it finishes.

Installing Microsoft 365 (formerly Office 365) with a product key is a straightforward process that links the license to your personal Microsoft account. Once linked, you don't need to enter the key again to reinstall the software. 1. Redeem Your Product Key