Try to use "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: Firefox > Quit Firefox; Linux: Firefox/File > Quit) to close Firefox if you are currently doing that by clicking the close X on the Firefox title bar.

See also:

• "Hang at exit": http://kb.mozillazine.org/Firefox_hangs
• "Firefox hangs when you quit it": https://support.mozilla.org/kb/Firefox+hangs

The problem persists. I've unchecked hardware accel. to no avail. It appears FF25 is also using a great deal of memory.

I am having the same problem as well. The version 25 process continues to run in background for long period of time after I close firefox application. I never had this problem with firefox 24 or lower. I am using Windows 7 (since other poster mentioned windows 8)

Same problem on Win7 and WinXP. Happened after upgrading to 25.0.

Any solution for this problem?????

No. I checked on line an tried all the suggestions; disabling addons ect. None worked. I'm so fed up with FF25 I plan on going to Chrome. On top of everything else, have you noticed the size of the memory leak.

Mozilla should really address the problem.

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

Thanks for the help, but it made no difference. Just to reiterate, FF24 worked great.

I haven't looked at the memory leak, just one more issue I guess.

I noticed that the problem seems to occur if you exit FF and then quickly attempt to restart it. It happens less frequently if you exit, wait a bit and the try to restart. I haven't tried to quantify the amount of time one should wait before attempting to restart FF, maybe I'll do that tonight. It seems that once FF gets in this state it must be killed via TM and not just by waiting for it to exit on its own (but maybe I just haven't waited long enough).

Like you, FF24 worked just fine for me. It was only after I upgraded to 25 that this problem showed up.

Does Mozilla support read these fora?

P.S. This is indeed very annoying.

One thing I've noticed is that as I trouble shoot, it happens always on the third time that I close FF. So who knows what is going on. I am disappointed that other than Cor-el, there has been no help from FF. This clearly is a problem with FF25 and yet no acknowledgement from FF. They broke it they should fix it.

I have been having this same problem for a few years and with different operating systems and builds. It seems to have started in V18 and never fixed. We are in V25 now and still this annoying issue persists. I have 2 desktop pc's that run Win 7, 2 laptops that also run Win 7, 2 laptops that run XP and one laptop that runs Vista and they are all different and have completely different memory modules and processors as each other. All my computers suffer from Firefox not closing down in the way it should and the process is left running in task manager. I brought this to the attention of Mozilla a few years ago and was simply told to shut the window down by clicking the Firefox logo at the top left of the window and selecting close from there. What is the point of that when we have a close button at the top right? Mozilla couldn't give me a satisfactory explanation as to why this was happening, or what was causing it. I got that fed up contacting Mozilla (over 2 months) that I changed to Google Chrome and even considered the evil one, internet explorer. 5 years on and Mozilla still haven't fixed this very pressing issue and the more I speak about this with friends, the more people seem to suffer with it. I have come to the conclusion that Mozilla aren't too interested in fixing this bug, so either use firefox and accept the crashes or install a more stable browser like Chrome. Firefox is a good browser when it is functioning as it should but after a few weeks/months of the install is when you will start having issues. In my experience, the only solution for the browser to function correctly again is to reinstall your operating system back on your computer and then install Firefox again. Too much messing around for me. I'm sticking with Google browsers for the forseeable future!

MOZILLA, PULL YOUR FINGER OUT!!

bootcampeddie, I completely agree with you. I've moved on to Chrome. FF is not interested in addressing this issue. A quick internet search shows how wide spread this problem is. And the lame solution of "click file, exit" is just BS. If mozilla can't even make the exit button work how are they going to fix this problem. Mozilla, I was a contributor, but not any longer.

SOLUTION (possible).

Hi all. I had this problem as well. I currently run FF26. A week or so ago, out of nowhere FF wouldn't exit - the window would close but firefox.exe process would keep running in the background using about 50% of CPU. Not sure if it's connected, but just prior to that I clicked on a link on Facebook that looked like spam website, nothing happened, site loaded (sort of, all I saw was a msg - Please Wait...) but nothing happened, I have Eset antivirus and it monitors network traffic and files for viruses, so maybe it prevented my PC getting infected...

So, I had this problem for a few days, was searching the net for solutions, but nothing seem to help. Then, just out of luck I did something that WORKED!

Here's what I did. I noticed that svchost.exe was using a lot of CPU alongside with FF. I ran ProcessExplorer to see what might be connected to this process, the list was long and I didn't have any idea where to start, so what I did was - Right click on svchost process, choose Debug and dismiss the warning. In a few seconds svchost process quit and after that FF started closing properly.

I had to re-enable all my plugins and themes I disabled prior, I also lost my history and preferences which I trashed in the process of searching for solution. But heck, it worked, hopefully for good. Now if someone could point out the real cause of this and fix it for everyone - that would be great. Cheers!

Thank you laserbeam for your post. I came across it after I ran some tests and discovered some info after about a day of messing around.

I must mention that I am running Win7x64 and although there are many other minor problems with my installation, I tackle them one at a time, trying to understand what is happening and solving them without ever reinstalling my OS. I am well versed at solving these type of problems given some incentive and time! I must stress the TIME part ... lol ...

When I invoked Safe Mode (via help) after observing the program remaining resident, the problem appeared to have left, but soon returned. I noticed that when I rebooted the first time after observing the problem, that FireFox was terminating correctly and the problem appeared to have gone away. However later (after some use), the problem came back. A few more Safe Mode tries (via holding down the Shift Key during invocation, because FireFox would never terminate correctly from then on) & reboots and I discovered that I could not get FireFox to terminate anymore, no matter what I did. I also restarted explorer.exe (DeskTop) and that wasn't helping, either....

... It appears that the problem is related to load order of things during boot up, if I were to hedge here. For some reason I was unfortunate that I couldn't get FireFox to terminate correctly, after that....

Now, after coming across your post, I tried what you had done and during this current reboot, the problem is gone ... Before I attempted it, I took a look at the slightly CPU Intensive copy of the particular svchost.exe that I performed it on, and there weren't too many other dependencies with my svchost.exe, and I should be able to narrow it down further, after some future reboots/tests ... That is where I am at the moment.

I would like to mention that when the problem occurs, I could see a slight memory leak via Task Manager and that determining the svchost.exe to attempt it on in memory, takes some observation via Process Explorer, but one will be able to determine which one to try this on...

I'll repost if I discover anything interesting, further.

Firefox simply won't close half the time for me too. Even on a new install to new Windows Server 2012 R2. Its terrible anymore.

Did you try a new profile and did you try to disable all plugins?

Create a new profile as a test to check if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

See also:

• https://support.mozilla.org/kb/Troubleshooting+plugins

go to task manager, then processes, then rt click on firefox process and from menu click on priorities. change normal to high close process. close task mgr. reboot. the firefox should work normally on shutdown...atleast mine is so far. note need to use system explorer as it lets you permanently set the priority to high. task manager will revert to normal after one use.