Teams Desktop Client does not support Personal Microsoft Accounts

Based on the reported behavior and the available Microsoft Q&A cases, this is a known issue affecting some Windows 10 systems in the Teams desktop app, where personal Microsoft accounts show:

“Personal accounts aren't supported yet in Teams (Preview).”

Supported conclusions from the available information:

1. This is not confirmed in the provided documentation as a permanent product limitation for all desktop clients. The issue is described in multiple Microsoft Q&A cases as affecting the Teams desktop app, while the same personal accounts continue to work in Teams on the web.
2. The behavior is consistent with a desktop-client-specific issue rather than an account issue. That matches the troubleshooting already completed: multiple accounts tested, multiple PCs tested, reinstall performed, and Teams web still works.
3. A documented workaround is available. The accepted workaround in the matching Q&A cases is:
   1. Uninstall Teams from Windows Settings > Apps.
   2. Sign in to Teams on the web.
   3. Select Meet to generate a meeting link.
   4. Open that meeting link in a new browser tab.
   5. On the Join your Teams meeting page, select Download now at the bottom and install the app from there.
   6. After installation, use the Sign in option in the installed app and test the personal account again.
4. If the issue is only a sign-in problem in the desktop client, Microsoft’s general Teams sign-in guidance also supports reinstalling Teams and, if needed, collecting debug logs and opening a support request. Since reinstall has already been tried, the next supported escalation path is to collect debug logs and create a support request if the workaround above does not resolve the issue.

For the specific questions:

• Known issue or limitation: Known issue in matching Microsoft Q&A reports; not established in the provided context as a general removal of personal-account support across all desktop versions.
• Recent support change in desktop versions: No official documentation in the provided context confirms a recent product-wide change removing personal Microsoft account support in Teams desktop.
• Expected behavior or defect: The available cases indicate this is treated as an issue in the desktop client, especially where web access still works.
• Workaround or fix: Use the meeting-link installation workaround above. If it fails, collect debug logs and open a support request.

References:

• Microsoft Teams Desktop: "Personal accounts aren't supported yet in Teams (Preview)" with every personal Microsoft account - Microsoft Q&A
• Issue logging in Teams desktop app on Windows 10. - Microsoft Q&A
• Personal accounts are not yet supported in Teams (preview) - Microsoft Q&A
• Resolve sign-in errors in Teams