Opening Task Manager Slows PC to Crawl - Windows 10 Pro 1709

Thank you for getting back to us. We've recommended the in-place upgrade process to maximize isolation of operating system based issues.

To further isolate your concern, we'd like to check if you've tried uninstalling the specified antivirus software and see if you still experience the same performance when using task manager on your device.

Note: Uninstalling an antivirus software makes your computer vulnerable to threats, we'd recommend turning on Windows Defender to secure your device.

We look forward to your response.

I did not try uninstalling my antivirus software, but I did try shutting down protection (Webroot), essentially turning it off.  On my laptop, that did seem to help, but on my brand new computer with 2 Xeon processors, 48g of RAM, and a 1 Terabyte SSD, freshly set up with a new installation of Windows 10 Professional, it made no difference whatsoever.

Thank you for getting back to us. We've recommended the in-place upgrade process to maximize isolation of operating system based issues. Performing this will usually fix broken system files/corruption brought about by the changes on your device.

The changes brought about by the Fall Creators Update (version 1709) may also have created a conflict with the specified antivirus software that resulted to the issue. Based on the posts on this thread, the antivirus software is the common program on the computers that were affected. Since turning it off did not make a difference, we'd like to check if you've tried uninstalling it and see if you'll still experience the same performance issue when using Task Manager. If the issue doesn't occur after removing the software, we'd recommend engaging the developer of the program to check for updates and/or compatibility with version 1709.

Note: Uninstalling an antivirus software makes your computer vulnerable to threats, we'd recommend turning on Windows Defender to secure your device.

We look forward to your response.

Lol.....this guy......

I second this.  I tested on 3 different computers, and the moment Firefox is opened, opening task manager causes it to slow the computer to a crawl.  Can't even move the mouse and I have to press ESC hoping the task manager will close itself then comp returns to normal.

Thank you for your suggestion. I appreciate you wish to help me to repair my Windows installation.

But - and it is a big 'but' - it was a Windows upgrade, the autumn creators' update, that broke Task Manager on my PC in the first place.

Task Manager did not conflict with anything on my PC until the autumn update. Since then, it conflicts with two major browsers ... though not Edge, funnily enough.

I would add that when the problem first manifested on installing the autumn update, I rolled back to the previous Win 10 build, which cured it. Reinstalling the update brought an immediate recurrence.

While I accept that this issue doesn't affect all machines, and that it may well be caused by legacy conflicts in my Win 10 installation (although SCANNOW finds no missing or corrupt files), my PC is my livelihood.

I'm sure you'll understand why I'm not willing to lose more business hours carrying out an in-place upgrade to cure the last update, especially as that route clearly carries its own significant risk of causing further disruption when one reads users' comments on the thread you linked to.

It's far more practical for me simply to accept that the autumn update broke Task Manager as far as my PC is concerned; disable TM and use a third party alternative.