Is Windows 11 KB5074109 Update Causing Outlook to Freeze or Hang? A Safer Path is to Migrate to Office 365

As part of its Patch Tuesday, Microsoft released the latest cumulative updates for Windows 11 – version 25H2 and 24H2 (KB5074109) - on 13th January, 2026. The update which is meant for fixing known issues has created more problems for the users. Many Windows 11 users who are using Classic Outlook with POP accounts started facing hanging and freezing issues with their application, after installing the latest update.

Here are some issues the Outlook users are facing after installing the update:

• Outlook is not exiting correctly
• Outlook hangs, freezes, or shows the "not responding" error
• Unable to reopen the Outlook application without ending its process in the Task Manager or restarting the system
• Sent Items folder not showing email messages already sent
• Outlook is re-downloading the emails

Windows 11 Update KB5074109 and the Issue – The Timeline

Here is the timeline of events occurred since the infamous update was installed on user systems:

• January 13: Microsoft released the Windows 11 Cumulative Update.
• January 15: Microsoft acknowledged that Classic Outlook users facing issues with the application and started investigating the issue.
• January 20: Microsoft provided an update that this issue may also occur for Outlook profiles that have PST files stored on OneDrive. It also suggested workarounds to move PST files from OneDrive to local storage and uninstall the Windows update. But            
• January 21: Microsoft is still investigating the issue. No permanent fix is available as of now.

Related Read: How to Fix Outlook Profile Hangs or Freezes after Windows 11 Update (KB5074109)?

Workarounds to Resolve the Outlook is Hanging/Not Responding Issue after Windows 11 Update

Microsoft is yet to provide a permanent solution to fix the issue. In the meantime, the company has suggested to use webmail or uninstall the update. Though uninstalling the Windows update temporary resolves the issue at hand, there are various risks associated with it, such as:

• By uninstalling the latest Windows update, you will also remove protection and fixes to mitigate vulnerabilities. This might expose your system to possible malware/virus infections and cyberattacks.
• If the latest security updates are missing, there is an increased risk of unauthorized access to your device and data.
• Cumulative updates also come up with other upgrades for stability and improved performance of the system. Uninstalling these updates can result in slow performance and frequent system crashes.
• By uninstalling these updates, you may lose access to crucial fixes and customer support services.
• In some situations, uninstalling the updates may lead to data loss.

Is there an Alternative to Rolling Back the Windows 11 Update?

There is an urgency for you to access your mailbox data and regain email communication. So you can try the temporary solutions but it has some risks as mentioned above. A permanent solution is to migrate to Office 365 (Microsoft 365) form your POP-based Outlook. This is a safest and long term approach you can consider.

There are traditional methods - Network Upload and Drive Shipping - to migrate PST files to Office 365 but these are lengthy, complicated, and time-consuming.

A simple and quick option to migrate PST files to Office 365 (Microsoft 365) is by using specialized PST to Office 365 migrator tool.

Stellar Migrator for Outlook is one such powerful tool that simplifies the PST to Office 365 migration process. It is a user-friendly tool that can easily be installed on any system and migrate PST files to Microsoft 365 accounts.

The software doesn't require MS Outlook to be installed or configured. It works independently of the Outlook desktop client and can easily migrate PST to Office 365 without any difficulties.

Salient features of Stellar Migrator for Outlook:

• Conveniently migrates PST files to Office 365
• Preserves mailbox folder structure and hierarchy during the migration
• Pay-per-use licensing makes it a cost-effective solution for large migration tasks
• Migrates PST files to Office 365 in varied scenarios
• Directly imports PST into Office 365
• Migrate PSTs from any system/s or network path
• Migrate encrypted OST and PST files
• Quick and simple target mailbox mapping
• Supports incremental migration, which minimizes data duplicity
• Shows real-time progress of the process

Watch this video to know the stepwise process to use Stellar Migrator for Outlook.

Conclusion

If you’re facing issues with your Outlook application after installing the latest Windows 11 update, rolling back the update is one of the suggested workarounds. However, it is not safe as it leaves the system vulnerable to virus and malware attacks. A safer alternative to this is to move mailboxes to cloud-based Office 365. Moreover, moving to Office 365 has a huge advantage – it helps users access their mailboxes anywhere, anytime, and from any device. To migrate your Outlook PST files to Office 365, you can take the help of Stellar Migrator for Outlook – a specialized PST to Office 365 migration tool.