Fix Task Manager Not Closing Properly in Windows 11 (Multiple Instances Bug)

Task Manager leaving orphan processes that slow down your PC? This known Windows 11 bug causes multiple taskmgr.exe instances to pile up. Here's how to fix it.

Published 2025-11-15 by TechNet New England

After installing Windows Updates released on or after October 28, 2025 (KB5067036), many users noticed a strange problem: closing Task Manager using the Close (X) button doesn't fully terminate the process. When you reopen Task Manager, the previous instance continues running invisibly in the background.

Over time, multiple instances of taskmgr.exe accumulate, consuming system resources and potentially degrading device performance. If you've noticed your PC getting sluggish and found multiple Task Manager processes running, this is why.

The Permanent Fix

Install the November 2025 Update or Later

Microsoft resolved this issue in KB5068861 (November 2025 security update). If you haven't installed it yet:

  1. Open Settings > Windows Update
  2. Click "Check for updates"
  3. Install KB5068861 or any later cumulative update
  4. Restart your computer

After updating to Build 26200.7171 or newer, Task Manager will close properly when you click the X button.

Workarounds (If You Can't Update Yet)

Method 1: Kill All Task Manager Instances via Command Line

Open Command Prompt or PowerShell as Administrator and run:

taskkill /im taskmgr.exe /f

This terminates all running Task Manager instances immediately.

Method 2: Use End Task Instead of the X Button

Instead of clicking the X button to close Task Manager:

  1. Go to the Processes tab in Task Manager
  2. Find "Task Manager" in the list
  3. Right-click it and select "End task"

This properly terminates the process rather than leaving it orphaned.

Method 3: Clean Up Orphaned Instances

If you already have multiple instances running:

  1. Open Task Manager (Ctrl+Shift+Esc)
  2. Expand "Background processes"
  3. Look for multiple "Task Manager" entries
  4. Right-click each one and select "End task"

How to Check If You're Affected

Open Task Manager and look at the Details tab. Search for "taskmgr.exe" - if you see more than one instance (when you only have one Task Manager window open), you're experiencing this bug.

You can also check your Windows build number: go to Settings > System > About. If your OS build is below 26200.7171, you likely have the bug.

Why This Happened

The bug was introduced in the October 2025 preview update (KB5067036). When you clicked the X button, Task Manager's window closed but the process didn't terminate properly. Each time you opened and closed Task Manager, another orphan process was left running.

Microsoft acknowledged the issue and confirmed the fix in their November 2025 release notes.

Need help with Windows updates or performance issues? Contact TechNet New England for IT support.