Issue
I was previously able to log into Microsoft 365 (Office) on my Windows 11 computer but I am no longer able to after repairing my computer. I had to replace the motherboard and CPU.
Environment
Microsoft 365 (Office).
Resolution
Please try using Microsoft's Support and Recovery Assistance (SaRA) tool to resolve the issue.
If SaRA doesn't resolve the issue, and you're encountering an error code 2147942402 or error code 29 when attempting to activate Microsoft 365, try the solution in Microsoft's Fix authentication issues in Office applications when you try to connect to a Microsoft 365 service article.