why is my Classic Outlook freezing up and then won't reopen without a full computer reboot?

Hey,

We've also been encountering the same problem for the last 3 days, and we finally figured it out.

If you're on Windows 11, Microsoft rolled out the following automatic update: January 13, 2026—KB5074109.

Go to Settings > Windows Update > Update History > find the update KB5074109 (would have been installed sometime between now and January 13th > and Uninstall that update. (Might have to scroll down).

It worked for us, hopefully it works for you.

So frustrating that things like this happen. We even tried to switch to Outlook New, but it won't let us import our Outlook PST files there, so we would lose all of our data. How programmers don't think of things like this is beyond me.

Good luck!

Hi @Mark Beyerle

Welcome to the Microsoft Q&A forum. 

Thank you so much for reaching out, and I’m really sorry that Outlook has been freezing and not responding on your side. I know how important it is to have your email working reliably. 

I understand how inconvenient it must be to repeatedly face Outlook freezing, duplicated message downloads and being unable to delete any items despite multiple attempts.  

After reviewing the details you provided, I’d like to let you know that this behavior matches an ongoing known issue affecting Classic Outlook profiles with POP accounts and PSTs hang after Windows updates on January 13, 2026. Our engineering team is fully aware of the issue and they are actively working on a fix to restore normal functionality as soon as possible.  

For your reference, you can follow updates and additional details in this article: Classic Outlook profiles with POP accounts and PSTs hang after Windows updates on January 13, 2026 

In the meaning time, you can try these steps in this link to migrate the issue: How to remove an Outlook .pst data file from OneDrive 

As community moderators, we kindly ask for your understanding that our access to internal development details is limited. Our primary role is to guide users toward the appropriate resources and support channels. While we may not have visibility into performing deeper backend analysis, we’ll continue doing our best to support you within the scope of our responsibilities.    

Additionally, as other users have raised similar concerns and may not be aware of where to share their feedback, I hope this response helps clarify the situation and suggests a potential next step. Highlighting this information can make it more visible to others in the community who may be facing the same issue, making it easier for them to find guidance and contribute their feedback as well. 

Thank you again for your time and for raising this important usability concern. If you have any further questions or need additional assistance, please don’t hesitate to reach out. 

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