Hello Sharon. With the "Focus" feature introduced via the August 2025 KB5063878, Windows 11 was reinforced as a platform to relieve users from distractions and manage notifications as well as integrate with Outlook and Teams. Unfortunately, the new Focus feature is available within Windows 11 and many users, like you, have found this feature to be restrictive and intrusive, especially when the feature interferes with: sidebar messaging, notification syncing, and limiting viewable apps on your devices. Unfortunately, Focus is now entrenched into Windows 11 productivity offerings and you cannot uninstall the feature. However, you can remove most of the features of Focus by going to and navigating in the settings to Settings > System > Focus, and turning-off all automation about Focus, including focusing-assist and notifications during focus. Also check your notifications settings under Settings > Notifications > Do Not Disturb, and if you have activated scheduled time for Do Not Disturb, deactivate the scheduled time as well. This will not "uninstall" Focus, but it will suppress Focus from activating and possibly encumbering your work.
Microsoft has not allowed for the removal of the Focus feature, but you can use the Microsoft Feedback Portal to leave feedback for Microsoft's consideration to remove it or give more control to the user in the future.
Best regards,