🚨 Task Manager Bug Strikes After KB5067036 Update

Microsoft’s latest optional Windows 11 preview update, KB5067036, has introduced a strange new bug: Task Manager won’t quit when you hit the “X.”

Instead, it silently stays active in the background, spawning multiple hidden taskmgr.exe processes every time you reopen it. Over time, this eats up memory, drags down performance, and can even confuse technicians who rely on Task Manager for diagnostics.

What’s Happening

The issue affects Windows 11 build 26200.7019 and 26100.7019. After installing the update, closing Task Manager doesn’t actually terminate it. Microsoft has confirmed the issue, saying:

“When Task Manager is closed, the process continues running invisibly, resulting in multiple lingering instances that can degrade device performance.”

Each “ghost” Task Manager process uses roughly 20–25 MB of memory, meaning frequent reopening can consume hundreds of megabytes or more.

Why It Matters for IT and Security Teams

This isn’t just a cosmetic annoyance — it has real implications for system stability and IT operations:

  • Hidden processes: Multiple unseen Task Managers can skew diagnostic data.

  • Resource drain: Adds memory overhead, especially on low-spec systems or VMs.

  • Forensic confusion: Technicians might misread system behavior during troubleshooting.

  • Patch risk: Highlights why preview updates should be tested, not auto-deployed.

At Equal Tech Solutions, we stress that even optional updates should pass a staging or sandbox phase before enterprise rollout — and this incident proves why.

How to Check if You’re Affected

  1. Go to Settings → Windows Update → Update History and confirm KB5067036 is installed.

  2. Open Task Manager (Ctrl + Shift + Esc).

  3. Click the X to close it.

  4. Reopen Task Manager.

  5. Under the Details tab, look for multiple taskmgr.exe processes — each with a unique PID.

If you see duplicates, you’ve got the bug.

Workarounds Until Microsoft Fixes It

Until a fix is officially rolled out, here are safe mitigations you can use:

🧰 Option 1: End Task Manager Manually

In Task Manager itself, select each Task Manager instance → click End task.

đź’» Option 2: Kill All Instances from Command Prompt

Run Command Prompt as Administrator and type:

 
taskkill.exe /im taskmgr.exe /f

⏳ Option 3: Reboot

A restart clears all hidden instances — though the issue will recur until patched.

đźš« Option 4: Defer the Update

Since KB5067036 is an optional preview update, you can safely defer it on production systems until Microsoft releases the fix in a cumulative update.

Microsoft’s Response

Microsoft has added this to its known issues list for the KB5067036 release notes and is currently investigating. Expect the fix to arrive in an upcoming November 2025 cumulative update or out-of-band patch.

Equal Tech Solutions Recommendations

For our clients and partners, we advise:

âś… Hold off on KB5067036 unless you require a specific feature it introduces.
âś… Add a monitoring rule for unexpected taskmgr.exe counts or high memory usage.
âś… Document the bug in your internal patch or helpdesk notes.
✅ Train staff to use “End task” instead of the “X” button when closing Task Manager.
âś… Notify end-users about the issue to avoid confusion or unnecessary support tickets.

Final Thoughts

Even small Windows updates can bring big surprises. The Task Manager bug in KB5067036 serves as a reminder that optional preview patches should be treated like beta releases — test first, deploy later.

At Equal Tech Solutions, we help businesses stay secure, stable, and ahead of unexpected update fallout. Whether it’s patch-testing, endpoint monitoring, or security configuration reviews, our technicians ensure your systems stay smooth and safe.

Stay secure. Stay updated — the right way.
For expert patch management and IT security support, contact Equal Tech Solutions today.