MS Classis Outlook Frozen

End the stuck Outlook process, start classic Outlook in Safe Mode, and then disable the component that causes the freeze; if Outlook still cannot start, use Microsoft’s Get Help service to reach technical support.

1. Start Outlook without add-ins

1. Press Ctrl + Shift + Esc to open Task Manager.
2. Select Microsoft Outlook or OUTLOOK.EXE, then choose End task.
3. Press Windows key + R.
4. Enter:

      outlook.exe /safe
   

5. Select OK, accept the default Outlook profile, and sign in if prompted.

If Outlook works in Safe Mode, an add-in is probably responsible:

1. Go to File → Options → Add-ins.
2. At the bottom, select COM Add-ins, then Go.
3. Record the enabled add-ins, then clear every checkbox. Do not select Remove.
4. Restart Outlook normally.
5. Re-enable add-ins one at a time, restarting Outlook after each one, until the freeze returns. Leave the problem add-in disabled. Microsoft documents this isolation procedure for classic Outlook freezes.^1^

2. Update Outlook and stop it reopening prior items

The unexpected “Reopen those items from your last session?” prompt was a documented issue affecting some perpetual Office installations beginning with Version 2306. It was fixed in Version 2309 Build 16827.20130.^2^

If Safe Mode opens:

1. Select File → Office Account → Update Options → Update Now.
2. Install the latest build offered for your Office release and update channel.
3. Restart Windows and test Outlook normally.

If Outlook opens long enough to change its startup setting:

1. Go to File → Options → General.
2. Under Start up options, set the restore-items option to Never reopen previous items, if available.

If that option is absent, Microsoft documents this registry workaround. Back up the registry first because incorrect registry changes can damage Windows or applications.

1. Close Outlook.
2. Open Registry Editor.
3. Navigate to:

      HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Preferences
   

4. Create or edit the DWORD (32-bit) Value named:

      ReopenWindowsOption
   

5. Set its value to 1, close Registry Editor, and restart Outlook.

This prevents Outlook from attempting to reopen items from the previous session. Microsoft notes that the workaround might not stop every occurrence, so continue with the next section if Outlook still freezes.^2^

3. Check the current Windows 11 POP-account issue only if applicable

A separate recent issue applies when all these conditions are true:

• The computer runs Windows 11.
• Outlook contains a POP email account.
• Settings → Windows Update → Update history lists KB5074109.

That combination has been associated with classic Outlook hanging or failing to exit.^3^ A matching Microsoft Q&A case reports that KB5078127 is the replacement fix: open Settings → Windows Update → Check for updates, install that update if offered, and restart Windows.^4^

Do not uninstall updates solely because Outlook freezes; this branch does not apply unless the Windows version, POP account, and KB history match.

4. Contact Microsoft technical support

Microsoft still provides support for home users, although the available option can depend on the Office product or subscription:

1. Open Microsoft’s Contact Microsoft customer support page.
2. Select the Personal account tab.
3. Under Microsoft technical support, select Get help.
4. Sign in with the Microsoft account associated with Office.
5. Enter:
   Classic Outlook freezes at startup after the reopen-items prompt
6. Complete the suggested troubleshooter. If it does not resolve the issue, select the offered contact option, which may include chat.^5^

Windows Get Help also contains troubleshooters specifically for classic Outlook startup and profile problems.^6^

Before contacting support, note your Windows version, Office product and build, email account type (POP, IMAP, or Exchange), and whether Outlook works in Safe Mode. Those details will determine the appropriate next repair.

References

1. Classic Outlook
2. Outlook unexpectedly prompts to reopen items from your last session | Microsoft Support
3. My classic Outlook keeps freezing - Microsoft Q&A
4. Oulook Classic Frozen Again - Microsoft Q&A
5. Contact Microsoft customer support | Microsoft Support
6. Resolve Outlook for Windows issues with automated troubleshooting tools | Microsoft Support