Same problem on a Win7 machine after upgrading to 36.0.1. Gone even a bit further: Uninstalled Firefox & my anti-virus program, deleted Mozilla dirs from Program Files and from AppData and cleared up the registry. Then reinstalled, still hangs on first click on a link. Impossible to kill process, only reboot helps.

If Firefox is uninstalled then it should no longer be present and if firefox.exe is not present it should not be able to run.

Of course although programs are installed on (usually) your hard disk they mainly run from and are in memory when in use. You should be able to kill processes with task manager. Fully closing down the machine and powering it off should also stop processes, but do NOT use the other options like hibernate, sleep, suspend or whatever. It appears you have already discovered rebooting solves the immediate problem.

1. Create a new additional profile. (Good practice do NOT delete or rename any profile you create)
   • Profile Manager - Create, remove or switch Firefox profiles
2. Do a clean reinstall, involving deleting program folders. (Do NOT delete the profiles - now at least two )
   • Firefox keeps crashing at startup_try-a-clean-install
3. Try running the newly reinstalled Firefox using the new Profile.
   • Initially use with all plugins disabled and do NOT use Firefox Sync
   • Do not initially try running external pages just use about:blank, close other tabs, then close and restart Firefox

Does that now run without hanging ? Please post back to say how you got on and what you tried.

Others seeing this problem please vote on this thread using the button [I have this problem too] (Some of you already have done).

• See also Firefox hangs or is not responding - How to fix

Then start your own question thread. Note in the past Firefox has had closedown issues, but AFAIK these are now fixed and it should almost always close down properly.

If you do post here please only either

• Post a solution you have found to work
• Post to say you have a similar problem and have started your own question (Please try to give full system information, in your own question. Use the troubleshooting add-on offered in the question workflow)

Anyone with very similar problems, please see my posts above. Please start your own question using this

• special link

Other contributors will recognise it as relating to this thread, and it cuts out a couple of steps.

Please try to give full troubleshooting information.

Hi berndf,

Sorry you are having problems. I know this can not be affecting everyone. I have tried Fx36.0.1 on Windows 7 and do not notice any particular problems, although it may possibly sometimes take a few minutes for Firefox to fully close down. I do not think there is a very big surge in this sort of question being seen on the forum.

If you don't mind please start your own question, that way we get your full details and can try to solve your problem. It is probable that there are multiple possible causes of this sort of issue.

I often try to avoid using Windows. Must admit I am not sure why processes may exist but not allow Task Manager to kill them (Presumbly we are talking firefox.exe here running under your own user name and not some system process) That is straying into a Windows topic, but it is directly relevant. Any Windows expert wish to enlighten me please ?

John99 said

I often try to avoid using Windows. Must admit I am not sure why processes may exist but not allow Task Manager to kill them (Presumbly we are talking firefox.exe here running under your own user name and not some system process) That is straying into a Windows topic, but it is directly relevant. Any Windows expert wish to enlighten me please ?

There are essentially two possibilities: 1. An uninterruptible I/O that doesn't finish. This has usually to do with stuck GDI resources. 2. Similar to UNIX "zombie processes", a dead process may remain in the process table, if another process still has a handle open to that process without listening for events on the handle.

Hi again Frank FrankPod said

UPDATE 2: Disregard update 1: The problem's still there: If the computer goes into sleep or hibernate, Firefox hangs when I wake it up and the problem proceeds as described. I think it's something to do with Firefox sync and/or various add-ons. I suppose I should now try the long process of gradually allowing sync permissions and add-ons until I find the particular one(s) that are causing the problem but I'd prefer not to! Any other sugestions? ....

Have you tried my suggestions upthread yet ?

If so you will have a new profile to use and experiment with.

This is not a cure but will make it easier if Firefox locks up in Windows. https://support.mozilla.org/questions/997866 {web link}

Thank you for all your support. Given the rapid succession of Firefox releases, I just waited for 37 to come out. My problem is gone now.

PS: Sorry, My mistake posted to wrong thread. I meant to post this here: https://support.mozilla.org/en-US/questions/1051150

That was very good work. Well Done. Please flag your last post as Solved Problem so other will know.