I used to be very satisfied with Firefox showing in Windows' task manager as a main process-tree with most of the browser's windows and several distinct processes, each connected to a specific window, that could be terminated separately to de-allocate resources without closing and losing the window itself.

Since last Windows' big update I only see a single process tree, but I can't terminate its "sub-processes" without having the whole program close. I can still terminate processes independently from Windows' resource monitor, but from there there is no way to distinguish the main process tree (which would close the whole program if terminated), making that route not viable.

These are few keys from about:support that show multiprocessing is activated:

Multiprocess Windows             69/69 (Enabled by default)
Web Content Processes            5/4
Multi-process staged rollout     3.05

NOTICE, that I can terminate some of the sub-processes in a way similar to what I intend to, but terminating one of them will reset several windows instead of only one and, most importantly, I can't distinguish the main Firefox process from the others and closing that one will close the whole program (while closing the other ones just "resets" a single windows).

This is a picture of the current situation, I'd expect those sub-processes each to have an independent process and the main process to keep those windows that don't have resources allocated to them.

enter image description here

This is a picture of how a window is supposed to look after the related process has been terminated.

enter image description here

Is there something I can do to revert to a situation where I can de-allocate each Firefox's window resources independently from the main process?

  • @Biswapriyo added the screenshot to the question – maja Jan 20 '18 at 4:12
  • That's new feature in Windows. It shows same processes in a group. Didn't you see their is multiple instances in task manager? – Biswapriyo Jan 20 '18 at 4:23
  • It' s not new, that's the way Firefox processes used to look several months ago. Also, I don't really care how they look, the point is I can't cherry-pick them for termination anymore. – maja Jan 20 '18 at 4:25
  • The point is: I don't know which one is the main process and which ones can be terminated safely to de-allocate memory, CPU usage, etc. – maja Jan 20 '18 at 4:26
  • 1
    with a tool like Process Explorer you'll see the hierarchy of processes - the top one will be browser process for the UI. – Biswapriyo Jan 20 '18 at 7:07

I can't distinguish the main Firefox process from the others

You can use Process Hacker:

A free, powerful, multi-purpose tool that helps you monitor system resources, debug software and detect malware.

Source Overview - Process Hacker

It is like Task Manager on steroids ...

One of the process views shows the hierarchy of processes.


enter image description here


I am not affiliated with Process Hacker in any way, I am just an end user of their software.

| improve this answer | |
  • Looks like an interesting alternative to Process Exploree, plus dibs for being open-source. – maja Jan 20 '18 at 23:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.