How to Prevent Outlook (New Version) from Installing with Windows 10 KB5051974 Update

With the release of Windows 10 cumulative update KB5051974 in February 2025, many users have reported the unexpected auto-installation of a new application: New Outlook. This highlights a key change, where users may find the new app listed in the Start menu after updating, yet it does not automatically launch or pin itself to the taskbar. This behavior has been confirmed by Microsoft as part of the update process.

New Outlook is based on Outlook.com, designed to be a more streamlined web application that offers several benefits over traditional Outlook or the Mail & Calendar applications. For instance, it is lightweight and includes full Copilot integration for enhanced productivity.

Despite these advantages, many users find New Outlook lacks the depth and advanced features of its predecessors, leading to dissatisfaction.

Steps to Prevent New Outlook from Auto-Installing on Windows 10

To avoid having New Outlook installed automatically with the KB5051974 update, follow the steps below:

Access the Windows Registry by searching for it in the Start menu.
Navigate to the following path in the Registry Editor: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsUpdate\Orchestrator\UScheduler_Oobe.
Create a new entry under this path by selecting New > REG_SZ and naming it BlockedOobeUpdaters.
Within BlockedOobeUpdaters, create a new value containing [“MS_Outlook” ].
After making these changes, ensure you close the Registry Editor.

Completing these steps will effectively block Windows from installing the new Outlook app. It is crucial to note that these registry adjustments are necessary as every subsequent Windows update will attempt to install New Outlook again.

For instance, if you’ve already installed KB5051974 and later uninstall New Outlook, this action is not permanent. The March 2025 update, for example, will reintroduce the app unless the above measures are applied.

Uninstalling New Outlook After Installation

If you’ve already undergone the February 2025 update and find New Outlook installed, here’s how to remove it:

Open Windows PowerShell with Administrator privileges via the Search or Start menu.
In the PowerShell (admin) window, execute the following command to uninstall New Outlook:

Remove-AppxProvisionedPackage -AllUsers -Online -PackageName (Get-AppxPackage Microsoft. OutlookForWindows).PackageFullName

This command uninstalls Outlook from the system while preventing it from reinstalling during future updates. Alternatively, if you prefer to uninstall the app only for current users, use the command:

Remove-AppxPackage -AllUsers -Package (Get-AppxPackage Microsoft. OutlookForWindows).PackageFullName

This second command will only affect the current user’s installation and will not prevent future installations. For effective long-term management of New Outlook, ensure that you implement the registry modifications outlined earlier.

Moreover, a special scenario exists where users may find themselves unintentionally installing New Outlook while utilizing the Mail & Calendar apps. With Microsoft discontinuing support for these applications, users will notice they can still receive pushes for New Outlook. To entirely block this installation, consider removing the Mail & Calendar app with the following command:

Get-AppxProvisionedPackage -Online | Where {$_. DisplayName -match "microsoft.windowscommunicationsapps"} | Remove-AppxProvisionedPackage -Online -PackageName {$_. PackageName}

Understanding Microsoft’s Strategy

The transition away from Mail & Calendar apps, coupled with the current limitations placed on classic Outlook for non-Microsoft 365 subscribers, leaves a gap that Microsoft aims to fill with New Outlook. This shift leads to the decision to enforce the installation of New Outlook via security updates.

Microsoft has clarified that the new Outlook does not replace previous versions and does not auto-launch upon installation. Implementing the registry block prior to the February 2025 update installation ensures the new app’s absence in your system.

For those users on Windows 11, be aware that newer builds (23H2 or 24H2) come with the new Outlook as part of the environment.

Frequently Asked Questions

1. Why is New Outlook being auto-installed with Windows 10 updates?

New Outlook is part of Microsoft’s effort to provide users with a default email client after discontinuing support for Mail & Calendar apps and is included in cumulative updates for accessibility.

2. What happens if I don’t take action to prevent New Outlook’s installation?

If you don’t follow the steps to block the installation, New Outlook will be automatically installed with each corresponding Windows update, potentially leading to usability issues if you prefer to use other email clients.