Microsoft has acknowledged a persistent issue affecting users of Windows 11 following the installation of the optional October 2025 update. Reports have surfaced indicating that the Task Manager remains active in the background, even after users attempt to close it using the “Close” button. This anomaly has led to a range of performance concerns, including system stuttering and CPU hangs.
Details of the Issue
According to Microsoft, “After installing Windows Updates released on or after October 28, 2025 (KB5067036), you might encounter an issue where closing Task Manager using the Close (X) button does not fully terminate the process.” Users have found that upon reopening Task Manager, the previous instance continues to run invisibly in the background.
This situation results in multiple instances of taskmgr.exe consuming valuable system resources, which can lead to noticeable performance degradation. These additional instances appear in the Processes tab labeled as “Task Manager” and in the Details tab as “Taskmgr.exe.”
While a few lingering Task Manager processes typically have a negligible impact on system performance, the issue can escalate when numerous instances accumulate unnoticed, potentially causing significant slowdowns in other applications.
Temporary Workaround
As Microsoft continues to investigate this matter, the company has provided a temporary workaround for users affected by the KB5067036 preview update. This solution involves manually terminating each process or using the Command Prompt to eliminate all instances simultaneously. Here’s how:
- Select Start or press the Windows key.
- Type cmd or Command Prompt in the search box.
- Select Command Prompt from the results.
- To run as administrator, right-click Command Prompt and select Run as administrator.
- In the Command Prompt window, type the following command and press Enter:
taskkill.exe /im taskmgr.exe /f
Additional Updates
The KB5067036 non-security preview update, released on October 28, introduced enhancements such as an updated Start Menu and the rollout of the Administrator Protection Windows security feature. As this is an optional update, users must manually install it unless they have enabled the “Get the latest updates as soon as they’re available” option, which facilitates automatic installation.
Moreover, this update has successfully restored functionality to the Windows 11 Media Creation Tool (MCT), which had ceased working on updated Windows 10 and Windows 11 Arm64 PCs following the installation of the Windows 11 2025 Update. It also addresses the 0x800F081F update errors that impacted Windows 11 24H2 systems after the installation of the KB5050094 January 2025 preview cumulative update and subsequent updates.
