365 ADD ON

Install Microsoft 365 on the existing Windows computer and sign in with the Microsoft account that owns—or has been invited to share—the Microsoft 365 Family subscription.

If this is your own computer

1. On the computer, open a browser and go to Microsoft 365 Apps.
2. Select Sign in and use the Microsoft account associated with your Microsoft 365 Family subscription.
3. Select Install apps > Install.
4. Open the downloaded installer and approve the Windows prompt.
5. Wait for “You’re all set! Office is installed now,” and then select Close.
6. Open Word from the Windows Start menu, accept the license agreement, and sign in with the same Microsoft account if prompted. This installs and activates Microsoft 365; you do not need to register the computer separately.^1^

If the computer belongs to another family member

The subscription owner must share Microsoft 365 with that person; do not give them the product key or the owner's account credentials.

1. The subscription owner opens the Microsoft 365 Services & subscriptions sharing page.
2. Select Share.
3. Send an Email invite, or select Create link and send the resulting link.
4. The family member accepts the invitation and selects Join now.
5. On their computer, they sign in using their own Microsoft account, select Install Microsoft 365 on all your devices, and run the installer.^2^

Microsoft 365 Family can be shared with up to five other people. If the invitee is already in another Microsoft family group, they must leave that group before joining yours.^2^

If Office is already installed

Open Word or Excel and sign in with the account associated with the subscription. If a trial or purchase screen appears, check that Office is signed in with the correct Microsoft account rather than an account that has no Microsoft 365 product associated with it.^3^

References

1. How to add a new PC (laptop) to my Microsoft 365 license? - Microsoft Q&A
2. Share your Microsoft 365 subscription
3. Activate Office for Windows | Microsoft Support