Particle.news
Download on the App Store

Windows 11’s Optional KB5067036 Triggers Task Manager Bug That Spawns Hidden Copies

Microsoft has not acknowledged the bug in the optional KB5067036 update, leaving users to rely on temporary workarounds.

Overview

  • Clicking the X to close Task Manager makes the window disappear but leaves taskmgr.exe running, and repeated use creates multiple background instances.
  • PC Gamer’s testing measured roughly 20–25 MB of RAM and up to about 1.5% CPU per instance, which can slow systems as copies accumulate.
  • The behavior appeared after the October 28 release of KB5067036 and has been documented by Windows Latest, PCWorld, PC Gamer, The Verge, Reddit users, and reporters.
  • Users can mitigate the issue by choosing End task in Task Manager or by running the command taskkill /im taskmgr.exe /f to shut down all instances.
  • The update’s notes reference a Task Manager grouping fix, yet as of October 31 Microsoft’s KB page lists no known issues and no fix has been released.