Troubleshooting Windows Task Manager: Resolving Issues Post-KB5067036 Update

Windows 11 Task Manager Bug Causing Performance Issues

Recently, Microsoft acknowledged a known issue affecting users who are unable to quit the Windows 11 Task Manager after installing the optional October 2025 update. The problem arises when the Task Manager continues to run in the background even after users attempt to close the app using the “Close” button. This issue has led to performance problems such as stuttering and CPU hang-ups.

According to Microsoft, the issue occurs after installing Windows Updates released on or after October 28, 2025 (KB5067036). When users try to close Task Manager using the “Close (X)” button, the process does not terminate properly. As a result, the previous instance of Task Manager remains active in the background without any visible window.

This issue leads to multiple lingering instances of taskmgr.exe, consuming system resources and potentially degrading device performance. These additional instances appear as “Task Manager” in the Processes tab and as “Taskmgr.exe” in the Details tab.

While having a few Task Manager processes running in the background may not impact most systems significantly, the accumulation of multiple instances can lead to noticeable slowdowns in other applications, as noted by Microsoft.

Microsoft is currently investigating the issue and has not yet released a fix. However, the company has provided a temporary workaround for users impacted by the KB5067036 preview update from last month.

Users can manually quit each process by selecting them in a new Task Manager window and clicking the “End Task” button, or they can terminate all processes simultaneously by following these steps:

1. Select Start​​​​​​ or press the Windows key.
2. Type cmd or Command Prompt in the search box.
3. Select Command Prompt from the results.
4. To run as an administrator: Right-click Command Prompt and select Run as administrator.
5. In the Command Prompt window, type the following command and press Enter: taskkill.exe /im taskmgr.exe /f

The non-security preview update KB5067036, released on October 28, includes an updated Start Menu and the rollout of the Administrator Protection Windows security feature. This optional update requires manual installation unless the “Get the latest updates as soon as they’re available” option is enabled.

With the release of KB5067036, Microsoft has addressed issues affecting the Windows 11 Media Creation Tool (MCT), which is now operational again following problems on up-to-date Windows 10 PCs and Windows 11 Arm64 PCs after installing the Windows 11 2025 Update.

The update also resolves 0x800F081F update errors impacting Windows 11 24H2 systems after installing the KB5050094 January 2025 preview cumulative update and subsequent updates.

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