outlook is frozen and not working

Question

Microsoft Outlook is not functional it is frozen. no emails in and i cant send emails.

Answer 1

Hi @Sophie Campbell,  

Welcome to the Microsoft Q&A forum. 

I’m sorry to hear that Outlook has been giving you trouble lately. To help me narrow down the cause and find a solution, could you please provide a few more details? 

• Is your mailbox configured as Microsoft 365/Exchange, IMAP, or POP? 
• Does it freeze immediately at startup, or only during specific actions (e.g., sending/receiving, opening shared folders)? 
• Can you access your email successfully via Outlook on the web? 
• Did this start after a recent Windows/Office update, a new add-in, or changes to your antivirus? 

In the meantime, please try these steps in order and kindly share with me the results: 

• Please try to force restart: Open Task Manager, end the Outlook process, and then reboot your PC. 
• Test with safe mode: Press Win + R, type outlook.exe /safe, and hit Enter. If it opens normally, an add-in is likely the culprit. 
• Manage Add-ins: If Safe Mode works, go to File > Options > Add-ins > choose COM Add-ins > click Go. Uncheck all items, restart Outlook, and re-enable them one by one to find the issue. 
• Check for hidden prompts: Use Alt + Tab to see if a dialog box is hidden behind another window. Also, check the bottom status bar for long-running processes (like large syncs or archiving). 
• Run Updates: Ensure both Windows and Office are fully up to date, as many "Not Responding" issues are resolved via official patches. 
• Creating a new Outlook profile (please just apply for exchange users)
  • Kindly refer to the detailed instructions: Create an Outlook profile - Microsoft Support  

When you reply, it will be greatly appreciated if you include the exact symptom (such as stuck on "Processing" vs. "Not Responding") and which of the above steps you have already attempted.

Note: For your security, please do not include your full email address or any sensitive personal information in your reply. 

Looking forward to your response.

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Answer 2

Follow these steps in order until Outlook starts working again.

1. Install latest Windows and Office updates

• Make sure Windows Update is set to install updates automatically.
• Install all important and recommended Windows updates.
• Install the latest Office/Outlook updates as described in Install Office updates.

2. Check if Outlook is busy with another process

• Look at the status bar at the bottom of Outlook.
• If it shows Outlook is using AutoArchive, syncing, or otherwise “in use by another process,” wait for that task to complete before trying to send/receive or click items.

3. Start Outlook in Safe Mode and disable add-ins

• Close Outlook.
• Press Windows key+R, type:
  • Outlook.exe /safe
  • Select OK.
• If Outlook works in Safe Mode:
  • Go to File → Options → Add‑Ins.
  • At the bottom, choose COM Add‑ins → Go.
  • Clear all check boxes → OK.
  • Restart Outlook normally.
• If Outlook now works, re‑enable add‑ins one by one until the freezing returns to identify the problematic add‑in.

4. Block external content in email

• In Outlook, go to File → Options → Trust Center → Trust Center Settings → Automatic Download.
• Turn on:
  • “Don’t download pictures or other content automatically in HTML e‑mail.”
  • “Warn me before downloading content when editing, forwarding, or replying e‑mail.”

5. Reduce mailbox and folder size

• Large folders can cause freezing.
• Create additional folders (Folder tab → New Folder) and move items out of very large folders (especially Inbox, Sent Items, Deleted Items).
• Optionally configure AutoArchive and compact data files using the guidance in the linked articles.

6. Check AppData redirection (if using roaming profiles or network redirects)

• Close Outlook.
• Press Windows key+R → type regedit.exe → OK.
• Navigate to:
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
• Double‑click AppData and set Value data to:
  • %USERPROFILE%\AppData\Roaming
• Select OK and close Registry Editor.

7. Repair Office installation

• Close all Office apps.
• Open Control Panel → Programs and Features.
• Right‑click Microsoft Office → Repair (or Change → Repair).
• Let the repair complete, then restart Outlook.

8. Repair Outlook data files

• Close Outlook.
• Run the Inbox Repair Tool (SCANSPST.EXE) and follow the steps in Repair Outlook Data Files (.pst and .ost) to scan and repair your data files.

9. Check antivirus integration

• Ensure antivirus is fully up to date from the vendor’s site.
• If it integrates with Outlook, temporarily disable only the Outlook integration or Outlook add‑in component (not real‑time protection) and test Outlook again.
  • Changing antivirus settings can increase risk; coordinate with IT/security before doing this.

10. Create a new Outlook profile

• Open Control Panel → User Accounts → Mail.
• Select Show Profiles.
• Select the existing profile → Remove (if appropriate) or leave it and add a new one.
• Select Add, give the profile a name.
• Enter user name, primary SMTP address, and password → Next.
• If prompted “Allow this website to configure … settings?”, check “Don’t ask me about this again” and choose Allow.
• Set the new profile as default and test Outlook.

11. Perform a Selective Startup (clean boot) if Outlook still freezes

• Open Control Panel → System and Security → Administrative Tools → System Configuration.
• On General tab, choose Selective startup and clear both “Load system services” and “Load startup items.”
• Re‑check “Load system services” → OK → Restart.
• If Outlook works, use the Services and Startup tabs to enable items one at a time, restarting each time, until the conflicting service or startup item is found.

If the environment uses POP accounts and Windows 11 was recently updated (for example to KB5074109), be aware there is a known bug where POP profiles hang and freeze after that update. In that case, uninstalling the specific Windows update (from Windows Settings → Windows Update → Update history → Uninstall updates) is the documented temporary workaround.

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References:

• Outlook not responding error or Outlook freezes when you open a file or send mail
• Outlook not responding, stuck at "Processing," stopped working, or freezes
• Outlook Freezing and Not Responding and Not saving changes when ending the task - Microsoft Q&A
• Outlook keeps crashing - Microsoft Q&A