Outlook freezes on basic tasks

Question

Hi,

Since Christmas Outlook has been a nightmare.

Reading emails, moving emails, sending emails just brings the spinning wheel. Even in safe mode it freezes.

I thought it was large PST files but I have removed them and the issue is the same. I have also compressed them, split them and repaired them.

What is annoying is you type an email, it goes to outbox, outlook crashes on send/receive and the email in the outbox goes and doesn't send and no way to get it back, it also makes me wonder what other emails haven't sent.

It is like something is happening in the background that keeps distracting it.

Any help would be great,

Cheers

[Moderator note: personal info removed]

Answer 1

Hi Chris Ridler,

Thank you for posting your question in the Microsoft Q&A forum. 

Please note that Q&A forum is a public platform, and moderators will modify the question to hide personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

Based on the symptoms you described, this behavior could be related to a known issue that affects Classic Outlook using POP accounts after installing the Windows 11 update KB5074109. Microsoft has published an advisory regarding this situation: Classic Outlook POP account profiles hang and freeze after Windows 11 update to KB5074109

Several users have reported the same problem, and many confirmed that removing KB5074109 allowed Outlook to function normally again.

If you find that KB5074109 is installed, you may want to consider uninstalling it and then restarting your computer. Here are the steps:

1. Open Settings > Windows Update
2. Choose Update history
3. Scroll down and select Uninstall updates
4. Locate KB5074109
5. Click Uninstall, then restart your computer

Note: Removing an update may reduce security posture temporarily, so if you’re in a managed environment, please coordinate with your IT administrator.

If Outlook stabilizes after uninstalling the update, you may want to prevent the update from reinstalling while Microsoft continues to investigate. Microsoft provides official guidance for temporarily pausing Windows Update: https://support.microsoft.com/en-us/windows/pause-updates-in-windows-643e9ea7-3cf6-7da6-a25c-95d4f7f099fe

Because security updates are important, I recommend using Pause updates only as a temporary workaround. Once a fixed update is available, please re‑enable updates and install the latest patches.

If, after considering the security implications, you still want to stop Windows Update more broadly, you can review this third‑party article for methods to disable updates. Note that these are not Microsoft‑recommended approaches and may reduce your device’s security posture: https://windowsreport.com/disable-windows-11-update/

Note: Microsoft is providing this information as a convenience to you. These sites are not controlled by Microsoft, and Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please ensure that you fully understand the risks before using any suggestions from the above link.

If your device is managed by an organization, local settings may be overridden by your IT policies, please coordinate with your IT admin as needed.

I hope this helps.

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Answer 2

Chris Ridler said

Since Christmas Outlook has been a nightmare

Can you please confirm the date when your problems started? The bad Windows Update KB5074109 was not release until Jan 2026.

Have you tried The Usual Suspects?

Open Outlook in Safe Mode
https://support.microsoft.com/en-us/office/open-outlook-in-safe-mode-f394c2ee-b2af-e97a-64ee-35cd24414811

Repair your Outlook Install
https://support.microsoft.com/en-us/office/repair-an-office-application-7821d4b6-7c1d-4205-aa0e-a6b40c5bb88b

Tested with a new Outlook Profile
https://support.microsoft.com/en-us/office/create-an-outlook-profile-f544c1ba-3352-4b3b-be0b-8d42a540459d