Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Sign-in is needed because the Microsoft 365 or Office license is tied to the account used to install and activate Office. When signed out, Office stays deactivated and files can be viewed or printed, but not created or edited until sign-in is completed.
To regain access to Excel on Windows:
- Open Excel.
- Go to File > Account.
- Select Sign In.
- Enter the Microsoft account that is associated with the renewed subscription.
If Excel freezes on the sign-in screen:
- Check Settings > Windows Update and install available updates.
- If a March 21, 2026 update named KB5085516 is available, install it. It was released to address a Microsoft account sign-in issue in some apps.
- Restart the PC and try signing in again.
If the account is not recognized or sign-in still fails:
- If the message says “We couldn't find an account with that username” or “account doesn't exist”, use the Sign-in Helper tool.
- If the account has not been used for more than two years, it may have been deleted and cannot be reopened.
- If needed, use the Microsoft account recovery form help.
If the subscription was renewed but Office still does not activate, make sure the same account used for the subscription renewal is the one being used in Excel.
References:
- About accounts in Office | Microsoft Support
- Sign in to Microsoft 365 | Microsoft Support
- Office for business
- I can't sign in to my Microsoft account | Microsoft Support
- Cannot sign in to excel or word - Microsoft Q&A When I try to open a document in Excel it asks me to sign in to my account. After I sign in I try to open an existing document in Excel and it requires another sign in then gives me an error saying I need internet to access. I have an active internet connection,.