The official release notes for the optional preview update "KB5067036" released on 202510/28 for Windows 11 version 24H2/25H2 state, "[Task Manager] Fix: Some apps may not be grouped with processes unexpectedly."
It seems that Microsoft tried to fix the process display (grouping) in Task Manager, but according to my own testing and reports from readers, after applying this KB5067036, the following side effect occurred:The process (Taskmgr.exe) remains even after closing Task Manager"Another new glitchIt was confirmed that this was occurring.
Verification: Even if it is closed, the process remains and continues to be recognized as existing
To verify this issue, first open the Task Manager three times (open one and then close it with the X button) and confirm that three processes are running.
Then, close the Task Manager window with the "X" button. Normally, this should end all three "Taskmgr.exe" processes.
However, when I checked this state using a verification program I created (an AutoIt script that obtains the status of all running "Taskmgr.exe" processes), I found some surprising results.
▼ Verification program execution results
The "Taskmgr.exe" processIt continues to remain without endingNot only that, the OS will mark those windows as "exist" (Log details: One of the three processes was "active" and all three were recognized by the OS as "existing")
This means that even if the user clicks the "X" button to close Task Manager, the process continues to run in the background (becoming a so-called "zombie process").
Impact (risk) of this defect
Don't underestimate it by thinking that "it's just a process that remains."memory leakmay cause.
Task Manager consumes a certain amount of memory and CPU resources to monitor the PC's operation. If you do not notice this problem and the process remains every time you open and close Task Manager,Memory usage keeps accumulatingAnd finally The overall performance of your PC becomes slow or unstableThere is a possibility.
approach
This issue is caused by a bug called "KB5067036"Optional Preview UpdatesPreview updates are test versions for advanced users who want to try out new features early, and are not something that regular users should install.
1. If you are installing now
- Do not install.
- Even though it is displayed as an "optional update" on the Windows Update screen, we strongly recommend that you ignore (do not install) "KB5067036" until Microsoft releases the next version of the update that fixes this issue (probably in the November monthly update).
2. If you have already installed it
- Uninstall "KB5067036":
- Open "Settings" > "Windows Update" > "Update History".
- Click Uninstall updates.
- Find "KB5067036" in the list and click "Uninstall."
- Restart your PC.
Let's hope this issue will be fixed in the next monthly update. Please share in the comments if you are experiencing the same issue in your environment.
Addendum: Additional verification
I tried some additional testing.
1. Force quit all "Taskmgr.exe" processes from Task ManagerEven ifOne process always remains
Even if you run "End Task" for all "Taskmgr.exe" from the Details tab of Task Manager,For some reason, one process always remains without terminating.This is a very strange behavior that can be confirmed using the Resource Monitor.
Moreover, thisCheck with older versionsI did it.
When "Taskmgr.exe" (Task Manager) detects an attempt to terminate itself (terminating "Taskmgr.exe" from within "Taskmgr.exe"),Intentionally leaving one processIt seems to be designed that way.
This may be a kind of self-defense mechanism to prevent the Task Manager itself from crashing.
2. The root cause was not "Taskmgr.exe" itself
From this behavior, the cause of the problem is "Taskmgr.exe"Is it in the file itself?Thinking about this, the author used "KB5067036" before applyingOlder versionsI replaced it with "Taskmgr.exe" and tested it.
However, the symptoms did not improve.
Based on this, I speculate that the root cause is not the "Taskmgr.exe" program itself, but rather that the "KB5067036" update introduced some kind of bug into the mechanism by which the OS manages and terminates the Task Manager process (probably the kernel or related services).
How to completely kill a zombie process
By the way, this "zombie process" cannot be terminated from the Task Manager itself, but you can force it to end using the following method.
- taskkill コマンド
- Right click on the taskbar icon > End task
- To use this feature, you must turn on End Task in Settings > System > Advanced.
- End the process from Resource Monitor
- Third-party process management tools
3. Side effects (glitches) discovered in Explorer
Upon further investigation, we found that this "KB5067036" was not only in the Task Manager but also in theExplorerIt has also been found to cause problems.
In the Explorer view settings, select "File nameextension"CloseEven if you do,.dll,.cpl,.bakSome files such asThe file extension continues to be displayedThis is the phenomenon.
This issue also occurs when you try "KB5067036"Uninstalling it returns to normalI have confirmed that.
"KB5067036" also included fixes related to Explorer, so like the Task Manager, it appears to be causing side effects (problems) in fundamental parts of the OS.
【in conclusion】
This "KB5067036" is a "problematic update" that may cause multiple system issues. Unless you want to test new Microsoft features, all users have no choice but to uninstall the program.This is the author's strong belief.
