Windows Task Manager Bug After KB5067036 Update
▼ Summary
– Microsoft confirmed a known issue where Windows 11 Task Manager doesn’t fully quit after installing the October 2025 optional update (KB5067036).
– Multiple lingering Task Manager processes can run in the background, consuming system resources and potentially degrading device performance.
– Microsoft is investigating the issue and provided a temporary workaround using Command Prompt to forcefully terminate all Task Manager processes.
– The KB5067036 update is optional and requires manual installation unless automatic updates are enabled.
– This update also includes fixes for the Media Creation Tool and resolves 0x800F081F update errors on Windows 11 24H2 systems.
Microsoft has acknowledged a significant problem affecting Windows 11 users who installed the optional KB5067036 update released in October 2025. This issue prevents the Task Manager from closing properly, causing multiple background processes to accumulate and potentially slow down system performance.
Numerous users have reported that clicking the “Close” button fails to terminate the Task Manager completely. Instead, the application continues running invisibly in the background, which can lead to system stuttering and CPU performance issues. Microsoft’s official documentation confirms that “closing Task Manager using the Close (X) button does not fully terminate the process,” creating multiple instances of taskmgr.exe that consume valuable system resources.
These lingering processes appear as “Task Manager” in the Processes tab and as “Taskmgr.exe” in the Details section of the Task Manager itself. While a few background instances might not cause immediate problems, Microsoft warns that dozens of accumulated processes “can cause noticeable slowdowns in other applications” and degrade overall device performance.
Although Microsoft continues investigating this known issue and hasn’t released a permanent solution, they’ve provided temporary workarounds for affected users. The simplest method involves opening a new Task Manager window, selecting each “Task Manager” or “Taskmgr.exe” process, and clicking “End Task” repeatedly until all instances are closed.
For a more comprehensive approach, users can employ the Command Prompt with administrator privileges. By opening Command Prompt as administrator and entering the command “taskkill.exe /im taskmgr.exe /f”, users can force-close all Task Manager processes simultaneously. This method effectively clears all accumulated instances with a single command.
The KB5067036 update, while optional, brings several important changes to Windows 11 systems. It introduces an updated Start Menu and begins the rollout of the Administrator Protection Windows security feature. Users must manually install this update by selecting “Download and install” unless they’ve enabled automatic update installation through the “Get the latest updates as soon as they’re available” setting.
Beyond the Task Manager complication, this update addresses several other system issues. It resolves problems with the Windows 11 Media Creation Tool, which had stopped functioning on updated Windows 10 PCs and Windows 11 Arm64 devices following the Windows 11 2025 Update. The update also fixes 0x800F081F errors that affected Windows 11 24H2 systems after installing the January 2025 preview cumulative update and subsequent updates.
Users experiencing performance issues after installing the October 2025 optional update should implement the provided workarounds while awaiting Microsoft’s permanent fix. Monitoring system performance and periodically checking for lingering Task Manager processes can help maintain optimal system operation until the underlying problem is resolved.
(Source: Bleeping Computer)
