Outlook Constantly Freezes

Question

Since around 1/14/26 I've had issues with Outlook Classic constantly freezing. To restart I've had to shut it down sometimes by killing the process and other times I've had to reboot for it to restart. I've spent at least 10 hours researching and applying fixes such as turning off add ons, repairing pst files, checking for update KB5074109 as others attributed to the issue to this (I don't see it in my update list), and attempting to auto archive and delete old email to reduce .pst file size which does not appear to work at all.

I even tried switching to "New Outlook", but I've lost all my contacts and it too randomly freezes.

I have a 1 year old HP Envy laptop that has plenty of memory and disk space.

I've read that this might be a Microsoft issue and there's no current fix.

Any insight would be appreciated as I'm about to switch to a webmail option, by I like Outlook.

Answer 1

It sounds like you're experiencing a frustrating issue with Outlook freezing. Here are some potential causes and solutions based on common issues:

1. Antivirus Software: If your antivirus software integrates with Outlook, it may cause performance issues. Consider disabling Outlook integration within your antivirus or disabling any antivirus add-ins in Outlook.
2. Large Mailbox Size: If your mailbox is too large, it can lead to performance problems. Try to reduce the size of your Outlook data file by moving items to separate folders or using the AutoArchive feature.
3. Corrupted Data Files: Corrupted .pst or .ost files can cause Outlook to freeze. You mentioned repairing .pst files, which is good. Ensure that you're also checking for any issues with .ost files if you're using them.
4. Conflicting Add-ins: Since you've turned off add-ons, ensure that there are no other conflicting applications running that might interfere with Outlook.
5. User Profile Issues: Sometimes, a corrupted user profile can lead to freezing. You might want to create a new Outlook profile to see if it resolves the issue.
6. External Content Loading: Outlook may freeze while loading external content, such as images in emails. Try disabling the automatic download of images.
7. Updates: Ensure that your Outlook is fully updated. If you don't see specific updates like KB5074109, it might be worth checking for any other pending updates or patches.

If you've tried all these steps and the issue persists, it may be worth considering reaching out to Microsoft support for further assistance or exploring alternative email solutions if necessary.

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References:

• Outlook not responding error or Outlook freezes when you open a file or send mail
• Outlook not responding error or Outlook freezes when you open a file or send mail

Answer 2

If you are using Classic Outlook with POP PST files

Update to the Support article

https://support.microsoft.com/en-us/office/classic-outlook-profiles-with-pop-accounts-and-psts-hang-after-windows-updates-on-january-13-2026-590fe356-ecc2-49f4-b9e3-bd39fafa58f6

Another workaround has been added - Move PSTs out of OneDrive

https://support.microsoft.com/en-us/office/how-to-remove-an-outlook-pst-data-file-from-onedrive-b6b9e522-59bd-40f7-949f-168d0aa9b38e

Once this is done, you should be able to unpause Windows Updates and let it put KB5074109 back.

Answer 3

If you have any POP email accounts, this is a know bug.

https://support.microsoft.com/en-us/office/classic-outlook-pop-account-profiles-hang-and-freeze-after-windows-11-update-to-kb5074109-590fe356-ecc2-49f4-b9e3-bd39fafa58f6

Temp fix is to uninstall the Jan 2026 Update KB5074109. If you can not uninstall this update thru normal means, see this thread for alternatives.

https://learn.microsoft.com/answers/questions/5707915/outlook-classic-not-opening-properly-or-recording

Answer 4

This seems to be an emerging problem with Outlook after the January Update, this is being reported by many people after that update, if you do not have that KB5074109 update installed, go to the Settings App - Windows Updates - Installed Updates, what is the KB number of the most recent updates installed?

.

Answer 5

2026-01-25 - A fix for the KB5074109 Outlook/OneDrive bug has been released as KB5078127.

https://support.microsoft.com/en-us/topic/january-24-2026-kb5078127-os-builds-26200-7628-and-26100-7628-out-of-band-cf5777f6-bb4e-4adb-b9cd-2b64df577491