cancel
Showing results for 
Search instead for 
Did you mean: 

2 firefox.exe running in the background whenever I open Firefox

SOLVED
Highlighted
New User

2 firefox.exe running in the background whenever I open Firefox

Whenever I open Firefox, there are two firefox.exe running the background whenever I open the browser. Whenever I try to close the second one, it crashes all of the tabs that are on the browser, and whenever I reload the tabs, it pops up again.

I've scanned my computer multiple times with multiple anti-viruses, but there was no viruses to be found. I've also disabled the plugins that I thought were the issue, and refreshed Firefox, but it was still there. I restarted my computer, no luck in doing that. Uninstalling and reinstalling Firefox didn't even do the trick either.

The double processes sky-rockets my RAM and CPU, and it's starting to get annoying. Please help! I appreciate any cooperation!

1 ACCEPTED SOLUTION

Accepted Solutions
SUMO Contributor

Re: 2 firefox.exe running in the background whenever I open Firefox

This could indicate that your Firefox is using a new "multiprocess" feature.

e10s

One of the headline changes in Firefox 48+ is e10s, which separates the browser interface process from the page content process. The performance impact of this can vary a lot between systems: many users find it faster, some find it slower, for many it's neutral. There probably is somewhat more memory use than when everything runs in a single firefox.exe process.

Are you using e10s?

You can check whether you have this feature turned on as follows. Either:

  • "3-bar" menu button > "?" button > Troubleshooting Information
  • (menu bar) Help > Troubleshooting Information
  • type or paste about:support in the address bar and press Enter

In the first table on the page, check the row for "Multiprocess Windows" and see whether the number on the left side of the fraction is greater than zero. If so, you are using e10s.

If you are using e10s:

If you think Firefox is not performing well or is using an unreasonable amount of resources now, you could evaluate whether e10s is causing this problem by turning it off as follows:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste autos and pause while the list is filtered

(3) Double-click the browser.tabs.remote.autostart.2 preference to switch the value from true to false

Note: the exact name of the preference may vary, but it will start with browser.tabs.remote.autostart

At your next Firefox startup, it should run in the traditional way. Any difference?

2 REPLIES
SUMO Contributor

Re: 2 firefox.exe running in the background whenever I open Firefox

This could indicate that your Firefox is using a new "multiprocess" feature.

e10s

One of the headline changes in Firefox 48+ is e10s, which separates the browser interface process from the page content process. The performance impact of this can vary a lot between systems: many users find it faster, some find it slower, for many it's neutral. There probably is somewhat more memory use than when everything runs in a single firefox.exe process.

Are you using e10s?

You can check whether you have this feature turned on as follows. Either:

  • "3-bar" menu button > "?" button > Troubleshooting Information
  • (menu bar) Help > Troubleshooting Information
  • type or paste about:support in the address bar and press Enter

In the first table on the page, check the row for "Multiprocess Windows" and see whether the number on the left side of the fraction is greater than zero. If so, you are using e10s.

If you are using e10s:

If you think Firefox is not performing well or is using an unreasonable amount of resources now, you could evaluate whether e10s is causing this problem by turning it off as follows:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste autos and pause while the list is filtered

(3) Double-click the browser.tabs.remote.autostart.2 preference to switch the value from true to false

Note: the exact name of the preference may vary, but it will start with browser.tabs.remote.autostart

At your next Firefox startup, it should run in the traditional way. Any difference?

New User

Re: 2 firefox.exe running in the background whenever I open Firefox

Thank you so much jscher2000! It helped me a lot!