First open teams.microsoft.com in a browser. If Teams works there, the problem is the app on your PC.
- Teams won't open. Press Ctrl + Shift + Esc, end every Microsoft Teams task, then start Teams again.
- Stuck on the logo or a blank window. Settings > Apps > Installed apps > Microsoft Teams > three dots > Advanced options > Reset. The first start afterwards is slow; that is normal.
- Messages won't send (red exclamation mark). This is almost always the network. Move to another spot in the office and try again.
- No notifications. Check, in order: Windows Do Not Disturb, Settings > System > Notifications (Teams allowed), your Teams status, and per-channel notification settings inside Teams.
- Teams is slow. Close extra browser tabs and apps. If only your older laptop struggles, let us know; it may be the hardware.
Full guide: https://sagesolutionsllc.net/blog/microsoft-teams-not-working/
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