Hi michael m,
Thank you for reaching out to Microsoft Q&A Forum. I understand how frustrating this is, especially after moving to a new Windows 11 computer and transferring everything from your previous device.
The steps already shared by Copilot are the correct and recommended first actions for this type of issue, and I’d encourage you to try them in the order provided.
At this stage, there aren’t additional troubleshooting steps I can reliably suggest beyond these. The behavior you’re seeing, Word and Excel logging you out instead of opening files, most commonly happens when the Office installation or sign‑in state didn’t transfer cleanly during the Windows 11 upgrade.
If the issue still persists after a full reinstall, the next appropriate step would be to contact Microsoft Support directly, as they can check your account sign‑in and licensing status on the backend, which we’re not able to access from here.
You can do that by Visiting https://support.microsoft.com/contactus> Briefly describe your issue > Enter > Scroll down and select "Contact Support" to connect with a live agent via chat or phone.
I know this isn’t an easy situation, but starting with the repair and reinstall steps is the best way to get Office working again on your new device.