Outlook not responding

Question

My Outlook keeps locking up (not responding). Ran Classic Outlook Advanced Diagnostics Troubleshooter. Got Report, made sure all software was current, Ran Glary Utilities on system, Outlook still locking up. I also dont know how to implement items in the report.

Answer 1

Dear @Stacey Aguiar,

Welcome to Microsoft Q&A Forum!

Thank you very much for taking the time to share the details and for running the Classic Outlook Advanced Diagnostics Troubleshooter. I completely understand how frustrating it is when Outlook continues to freeze even after you’ve already tried several tools. I appreciate for your patience.

The Classic Outlook Advanced Diagnostics Troubleshooter is designed to detect and report these common problem areas. However, it may not automatically fix all issues. Instead, it generates a report and points to the corrective actions that need to be performed manually. This is why Outlook may still freeze even though the report was successfully created.

Therefore, I suggest that you should try other solutions (option 2 and 3) in this article: Outlook crashes or stops responding when used with Office 365 to see if they can help.

Also, I can see that the Q&A Assist AI stated several suggestions that you can try as well, I recommend that you can try Safe Mode method. Reference: Open Outlook in safe mode

I hope the solutions above work for you, if not, you can try creating a new Windows profile:

• Close all applications
• Go to Settings (in Windows icon) > Accounts.
• Click on the Family & other users option.
• Click on Add account button.
• There are two options:
  • Microsoft account: Log in your Microsoft account.
  • Offline account: Create a new local account (Fill in username, password, and password hint)
• You can set up role for the new profile (Administrator or Standard User)
• Then you can try signing into Outlook again.

If Outlook remains unresponsive after completing all the steps above, I recommend contacting Microsoft Support through the Microsoft 365 Admin Center (if this is a business account). This allows Microsoft engineers to collect detailed logs and perform backend diagnostics that aren’t accessible through community support or automated tools.

As a Microsoft Q&A moderator, my role is to guide discussions and connect users with helpful resources. While I don’t have the right to access to individual account or your environment in order to help you further due to security protocols, only Microsoft support agents can check and assist you for it. However, I still try my best to support you using the resources available. So, please take a look in these suggestions above and contact them if applicable. 

Please know that you’ve already taken the right first steps by running the diagnostics, and I truly appreciate your efforts. I hope this information can give you some insights and please let me know how things go on your side as your update can also assist others in the community who may be facing the same issue.

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Answer 2

Outlook hanging or freezing is typically caused by outdated components, add-ins, large/corrupt data files, profile issues, or conflicting software. The Classic Outlook Advanced Diagnostics report already checked many items; the next steps are to systematically apply the standard fixes that align with the documented causes.

Follow these steps in order (testing Outlook after each):

1. Confirm latest Outlook and Office updates

• Ensure all Office/Outlook updates are installed as described in the Outlook performance guidance. Keeping Outlook fully updated addresses many known hang/freeze bugs.

2. Address common “not responding” causes The documented causes for Outlook freezing include:

• Outlook in use by another process
• Outlook loading external content (images)
• Interfering add-ins
• Mailboxes that are too large
• AppData redirected to a network location
• Damaged Outlook data files (.pst/.ost)
• Outdated or conflicting antivirus
• Corrupted Outlook profile
• Other conflicting programs

Use the steps from the “Outlook not responding error or Outlook freezes when you open a file or send mail” article (for Outlook 2010 and later) referenced in the performance article. In particular:

• Start Outlook in Safe Mode (already tried) to rule out add-ins. If Safe Mode is more stable, disable non‑Microsoft add-ins in classic Outlook.
• Reduce mailbox size by archiving or moving old mail if the mailbox is very large.
• Repair Outlook data files using the built‑in repair tools described in the crash/performance guidance.

3. Create a new Outlook profile If the profile is damaged, Outlook can hang or freeze even when everything else looks correct.

Steps:

1. Open Control Panel → Mail.
2. Select Show Profiles.
3. Select the existing profile and click Remove (only if data is known to be backed up or stored on the server; otherwise skip removal and just add a new profile).
4. Click Add and enter a name for the new profile.
5. Enter user name, primary SMTP address, and password, then click Next.
6. If prompted with “Allow this website to configure alias@domain server settings?”, check Don’t ask me about this website again and click Allow.
7. Enter credentials when prompted and click OK.
8. When setup finishes, click Finish and set the new profile as default.
9. Re‑run Classic Outlook Advanced Diagnostics if needed If Outlook still hangs after creating a new profile and applying the performance steps:

• Re‑run the Classic Outlook Advanced Diagnostics troubleshooter from the same Windows 10+ device where classic Outlook is installed.
• In the Get Help app, review the “Issues found” and “Detailed View” sections; they map directly to the known causes (add‑ins, data file size/corruption, profile, antivirus, etc.). Apply any specific fix it lists (for example, disabling a particular add‑in or repairing a specific data file).

5. If performance is still slow Use the additional guidance from the Outlook performance article:

• Confirm again that the latest updates are installed.
• Apply the methods in the “How to troubleshoot performance issues in Outlook” article (large PST/OST, Windows Search indexing, RSS feeds, To‑Do Bar, antivirus interaction, Skype for Business integration, etc.).
• If Outlook is integrated with Skype for Business/Lync, temporarily disable that integration as described to see if performance improves.

If, after these steps, Outlook continues to freeze, the next step is usually to share the SaRA report and environment details with Microsoft Support or post them (sanitized) in Microsoft Community for targeted guidance, as suggested in the crash/performance articles.

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References:

• Outlook not responding error or Outlook freezes when you open a file or send mail
• Outlook performance is slow in the Microsoft 365 environment
• How to troubleshoot issues that cause Outlook to crash or stop responding when used with Microsoft 365
• How to troubleshoot performance issues in Outlook
• Outlook crashes or stops responding when used with Office 365