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firefox.exe cannot be killed (terminated) at all except by restarting computer (Windows)

  • 3 replies
  • 2 have this problem
  • Last reply by jscher2000

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I have encountered a very very strange problem with the latest versions of Firefox (currently on 36 but I also saw this on 35, maybe 34). After using Firefox (not sure if putting my Windows 7 computer on standby for hours, possibly days could have an effect), when I exit Firefox, the firefox.exe process remains in the process list in Task Manager. And I cannot end or terminate it! I have tried everything from the simple End Process/End Process Tree in the regular Windows Task Manager to a full suite of termination attempts in Process Hacker.

The firefox.exe VERY VERY STUBBORNLY continues running. I have even tried to unload all the modules the process has loaded (over a 100 of them) but the process did not budge. I also closed all the handles the process is holding, except one which kept throwing an error (even after I removed the Protected flag on it).

The only solution to this problem is to restart my computer - admittedly inelegant especially when I rarely restart it. I am not able to start Firefox until I restart the computer as a new start attempt will first complain that firefox.exe process is already running, and when ignored, complain that the profile could not be accessed - and thus quit. I am making this feedback through Chrome which I have to use for now until I restart the computer next time.

I don't have a dump right now, as I basically screwed up all the memory of the process in all my attempts in Process Hacker. Maybe I'll make one the next time. But I have managed to see that the there is one thread for this process, and I have attached a screenshot of the stack for this thread - if it's any help.

I also don't know exactly how to reproduce it, except run Firefox for a long time (and possibly set the computer on a long sleep).

I should also make a special note that before this problem was encountered, Firefox was unable to access the internet connection at all. It would remain stuck at the spinner in all pages - the reason why I wanted to exit/restart it. This is despite all other internet connection tests passing.

Also, I did a search on "afd.sys", it is "Ancillary Function Driver for WinSock". I'm not sure how this affects Firefox. I cannot stop or restart this service.

Attached screenshots

Modified by ADTC

All Replies (3)

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Sorry . . . Wrong post.

Modified by FredMcD

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“All sites stop loading after Firefox is open for a period of time.” Possible Fix;

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I think you have explored this to a greater depth than anyone else I've seen. Here are two other recent threads about Firefox being "unkillable" -- neither has led to a satisfactory explanation:

In the first (older) thread, the problem did not occur in a new Firefox profile, suggesting that something in the settings folder (a preference, a corrupted or locked settings file, an extension, something else..) could be the culprit.

Here is how to test for that:

Create a new Firefox profile

This is in addition to and does not replace your existing settings.

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should come with completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run) -- type or paste the following and press Enter:

firefox.exe -P

Don't delete anything here.

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button, assign a name like March24, and ignore the option to change the folder location. Then start Firefox in the new profile you created.

It might take a while to determine whether the new profile is works better than your old one. If you want to import your bookmarks from your regular profile during that time, here's how:

You can use the Library dialog (Ctrl+Shift+b or "Show All Bookmarks") to access the Restore feature. The trick is knowing where to find your bookmark backups in your regular profile. After clicking Choose File... you can paste this into the file name space and press Enter to drill down to your profile folders:


The semi-randomly-named folder that has your last backup is usually the one ending with "default". Click into that one, then into the bookmarkbackups folder. Here you can pick the most recently updated file to restore.

Important: a Restore wipes any bookmarks currently in your active Firefox profile and replaces it with the contents of the restored backup.