Outlook will not open or keeps crashing

Steps to try when Outlook freezes, closes or will not start.

Updated September 21, 2026

  1. Wait two minutes. Outlook can be slow to start, especially after an update.
  2. Close it fully. Press Ctrl + Shift + Esc, find Outlook in the list, select it and choose End task.
  3. Open Outlook again while holding the Ctrl key. If it asks whether to start in safe mode, choose Yes.
  4. If it opens in safe mode, close it and start it normally. That sometimes clears the problem.
  5. Restart your computer.

In the meantime you can keep working. See Use Microsoft 365 in your web browser to reach your email from a browser.

Good to know

If it still fails, tell us what message appears, and whether the problem started after an update.