Windows 11 Bug: Task Manager Refuses to Close, Multiplying Processes and Hitting Performance

Windows 11 users on version 24H2 or 25H2 may notice several Task Manager processes running at once, each consuming around 20 MB of memory and a small slice of CPU. The issue stems from a bug introduced by a recent non-security preview update, which prevents Task Manager from fully terminating even after the window is closed, with each launch spawning another instance. For Sleep or Hibernate users, this can lead to a gradual accumulation of background processes that degrade overall performance.

Microsoft has not yet identified the precise cause but says a permanent fix is in development and expected to be included in the upcoming “B” release stable update later this month. In the meantime, a workaround is to end the Task Manager process manually, or to use an administrative Command Prompt to run taskkill.exe /im taskmgr.exe /f, and a full system restart may also resolve the issue. According to the article, those who avoid manual checks for updates may not receive this patch by default.