Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
The PIN prompt is not a Mac PIN. In this scenario, the PIN is typically a device-specific Windows Hello PIN, and it does not transfer from a Mac to a PC.
For Microsoft 365 Family sharing, the other person should usually accept the invitation and install Office with their own Microsoft account, rather than signing in on the PC with the subscription owner’s device PIN. A similar Microsoft Q&A case states that the PIN is device-specific and that sharing is normally done by inviting the other person to use their own account.
If the prompt is happening on the Windows PC, use one of these paths:
- On the sign-in screen, look for Other ways to sign in, Sign-in options, or Use your password.
- Sign in with the Microsoft account password instead of a PIN.
- If Windows is asking for a Windows Hello PIN on that PC and the PIN was forgotten, sign in to Windows first, then go to Settings > Accounts > Sign-in options > PIN (Windows Hello) > I forgot my PIN.
If the issue is that Office is not associated with the correct account, make sure the subscription is linked to the Microsoft account that owns it. For home products, the account association is part of the setup flow, and once linked, the install page shows My Office Account with the account email and install options.
For live help, Microsoft Support can be reached through Contact Microsoft Support. The support article also notes that support agents cannot send password reset links or change account details.