Microsoft Acknowledges Windows 11 Task Manager Bug That May Be Impacting Performance

Microsoft has officially acknowledged the findings from Windows Latest regarding a significant performance issue in Windows 11. In their statement, the company revealed that a bug exists, causing the Task Manager to remain active in the background even when users attempt to close it. This ongoing operation can consume crucial system memory, leading to decreased performance. This problem has been identified in the optional Windows 11 update KB5067036 (versions 26200.7019 / 26100.7019).

KB5067036, which is an optional update for Windows 11 versions 25H2 and 24H2, requires users to manually select the ‘Download & Install’ option for installation. Despite being optional, this update is noteworthy as it introduces enhancements such as the much-anticipated new Start menu feature, enabling users to disable the Recommended feed.

New Windows 11 Start menu with Recommendations turned off

The October 2025 update also revamps the taskbar with colorful battery icons and other features, resulting in a rush among users to download the update, despite Microsoft’s lack of warnings about the potential instability of such optional updates.

Understanding the Task Manager Bug

The KB5067036 update was released on October 28. Shortly after, tests conducted on October 30 revealed that the update inadvertently disabled the close button functionality in Task Manager. Attempting to close the application merely minimizes it to the background, remaining operational and consuming resources.

This ongoing operation of Task Manager can lead to significant resource consumption, particularly if a user opens multiple instances without rebooting their PC. Microsoft confirmed that users may experience issues as these background processes, labeled as taskmgr.exe, continue to run.

The Impact on System Performance

Tests by Windows Latest showed that repeatedly opening and closing the Task Manager exacerbates the performance issue. On the morning of Halloween, an extensive test involved closing Task Manager 500 times, with numerous processes remaining active. Each instance consumes approximately 20MB of RAM; while this may seem insignificant on a system with 32GB of RAM, the cumulative effect of 500 instances can lead to severe slowdowns.

Even though the average user might not open Task Manager hundreds of times, there are scenarios where prolonged operation without rest may occur, ultimately impacting performance. Microsoft reiterated that while a few active Task Manager instances have minimal impact on overall performance, numerous lingering processes can significantly hinder other applications.

Identifying Performance Issues with Task Manager

To check if your system is experiencing these performance problems, access Task Manager via the Ctrl + Shift + Esc shortcut or by right-clicking the Taskbar. Click the close button “X” several times without fully closing Task Manager. If you see multiple instances of Task Manager running in the Processes tab alongside high memory usage, your system is affected.

Note: Task Manager is not intended to have more than one active instance.

To resolve the issue, manually select and terminate each Task Manager process. Alternatively, you can expedite the process by executing a simple command in an elevated Command Prompt:

taskkill.exe /im taskmgr.exe /f

This command will ensure all instances of Task Manager are shut down. Moving forward, be sure to utilize the End Task feature to avoid the issue, but note that this is a temporary workaround until Microsoft releases a full fix in the upcoming update. Microsoft has not yet indicated whether an additional out-of-band update for Windows 11 versions 25H2 and 24H2 will be forthcoming.

Source & Images