Outlook Not Working Why ?

Common causes for classic Outlook not opening or freezing include:

1. Install the latest Windows and Office updates. Outlook freezing or not responding is commonly caused by missing updates.
2. Check whether Outlook is stuck on a hidden dialog box. Use Alt+Tab to see whether a confirmation window is open.
3. If Outlook shows Processing, wait a few minutes if it is working on a large move or delete operation.
4. Start Outlook in safe mode:
   • In Windows 10, open Start, type Outlook.exe /safe, and press Enter.
   • Then close Outlook and open it normally.
5. Repair Office:
   • Close Microsoft 365 apps.
   • Open Control Panel > Programs and Features.
   • Right-click Microsoft Office 2016 and select Change.
6. Repair Outlook data files using the Inbox Repair Tool (SCANPST.EXE). Exit Outlook first, then follow the repair steps in the Outlook data file repair article.
7. Create a new Outlook profile if the current one is corrupted:
   • Open Control Panel > Programs > User Accounts > Mail.
   • Select Show Profiles.
   • Select Add to create a new profile.
   • Restart Outlook and choose the new profile.
   • Removing a profile deletes offline cached content, so back up data files first.
8. If antivirus integrates with Outlook, it can cause performance issues. Disabling Outlook integration or Outlook antivirus add-ins can help.

Important: changing antivirus settings can make the PC more vulnerable to malicious software. Use that workaround only if necessary.

A guided troubleshooter is also available for classic Outlook on Windows 10 or later, and it must be run on the same Windows PC where classic Outlook is installed.

• Outlook not responding error or Outlook freezes when you open a file or send mail
• I can’t start Microsoft Outlook or receive the error “Cannot start Microsoft Outlook. Cannot open the Outlook Window” | Microsoft Support
• Outlook not responding, stuck at "Processing," stopped working, or freezes