Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox hangs upon startup, or starts a process but doesn't open the browser.

  • 15 replies
  • 39 have this problem
  • 1177 views
  • Last reply by Surfer3907

more options

Within the last couple days, Firefox has had a lot of problems.

When I open it, the window hangs and freezes after a few seconds, if it opens at all. Other times, trying to open Firefox simply won't open the window, but will leave an extra process running in the background that I have to manually shut down via Task Manager.

I have made a fresh profile. I have restarted Firefox. I previously had hardware acceleration checked, and disabled it; still having the same problem. I have uninstalled and re-installed Firefox multiple times. I have run a scan of my system with Malwarebytes; nothing detected. It's not even generating a crash log. I have looked through the support forums, found people with problems similar to mine, but no solutions posted for them since sometime last month.

Firefox seems to run normally if do an install of version 21, which opens up the browser window. Everything works fine, until I close the browser and then re-open it.

Within the last couple days, Firefox has had a lot of problems. When I open it, the window hangs and freezes after a few seconds, if it opens at all. Other times, trying to open Firefox simply won't open the window, but will leave an extra process running in the background that I have to manually shut down via Task Manager. I have made a fresh profile. I have restarted Firefox. I previously had hardware acceleration checked, and disabled it; still having the same problem. I have uninstalled and re-installed Firefox multiple times. I have run a scan of my system with Malwarebytes; nothing detected. It's not even generating a crash log. I have looked through the support forums, found people with problems similar to mine, but no solutions posted for them since sometime last month. Firefox seems to run normally if do an install of version 21, which opens up the browser window. Everything works fine, until I close the browser and then re-open it.

Chosen solution

Just out of curiosity, could this behavior (hanging on launch after a Windows Update) be a registry issue? If so then how could we check?

Hmm. I reckon it's nice that my post is a Chosen Solution. Now if someone would just tell me what the solution is....:)

Read this answer in context 👍 0

All Replies (15)

more options

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

To Enable SafeMode

  • You can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
  • Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.
  • Once you get the pop-up, just select "'Start in Safe Mode"

If it works in Safe Mode and in normal mode with all extensions (Tools > Add-ons > Extensions) disabled then try to find which extension is causing it by enabling one extension at a time until the problem reappears.

Close and restart Firefox after each change via "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: "Firefox > Quit Firefox"; Linux: "Firefox/File > Quit")

more options

Hi, try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) and check firefox again.

(If works in Windows Safe mode then you have a problem with other software, like security software or maybe a system driver, that is running on your computer).


thank you

more options

Thank you!

I rebooted the system in safe mode, and Firefox seems to work just fine, so the problem is what you suspect. What should I do now? What drivers should I look at?

more options

I tried a system restore to get rid of the driver problem - all that did was erase all my bookmarks.

more options

Seek for places.sqlite file in profile folder, when you locate the places.sqlite file, then you can remove it in a new profile.

(places.sqlite file stores the bookmarks, favorite icons, history, keywords, and browsing history)

see also : Finding your bookmarks


thank you

more options

Well, since I've already lost all my bookmarks and saved passwords, I did a complete and full uninstall/reinstall. No go.

I can't system restore to get rid of whatever driver problem is causing the hangs. I've set Firefox to start with all plugins disabled and that still didn't work. It only works if I go through a fresh install each time I want to use it.

Thinking of just moving to Google Chrome.

more options

Which security software (firewall, anti-virus) do you have?


It is possible that your security software (firewall, anti-virus) blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:


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

more options

I'm having a very similar set of problems, but with a few (possibly important?) differences. I am running Win 7 and Firefox 21.

In my case, Firefox hangs on launch. It does launch - there is an active process (two, in fact, counting the plug-in container) - but the window almost never opens. On the rare occasion that it does, the window is blank and non-responsive. In all cases I have to kill Firefox using the Windows task Manager.

So far I have tried...

1) Starting Firefox in Safe Mode. 2) Resetting Firefox. 3) Starting Windows in Safe Mode, then starting Firefox 4) Starting Firefox in Safe Mode while Windows is in Safe Mode. 5) Complete clean re-install (including deleting the Mozilla Installation folder).

In all cases but the last, the result is the same: a hung process that must be killed manually. A clean re-install lets Firefox start normally, BUT as soon as I restart Windows the hanging behavior returns.

I've done all I know to do. Any suggestions?

more options

I have the identical issue. More information: I experience this problem after every windows update. There are two accounts on this laptop; I log off one account, do the windows update on the other. FF works there but fails as above on the first account. A FF reinstall there fixes that account (after another FF-demanded & forced reboot), but now the second account's FF is broken and must also be reinstalled and rebooted.

As per other discussions on this (or related) topic, I've also opened the Windows Firewall to Firefox (scary!), made the Firefox appData profile folder not readonly (was actually only partially checked) and disabled hardware acceleration.

more options

Yes, I should have mentioned the update issue. I restart my computer much more often due to Windows updates than for any other cause, and I noticed that pattern as well.

more options

Chosen Solution

Just out of curiosity, could this behavior (hanging on launch after a Windows Update) be a registry issue? If so then how could we check?

Hmm. I reckon it's nice that my post is a Chosen Solution. Now if someone would just tell me what the solution is....:)

Modified by psuliin

more options

thanks, your post helped. turns out the addon mediahint was the culprit. after disabling it, firefox starts without hanging.

more options

Hmm. I don't have mediahint on my system. So we might be looking at multiple causes.

more options

No solution works so far, and it's getting worse. I had completely purge FF and did a full reinstall, which seemed to work. Then, with only one account logged on, and without Firefox running *at all*, I experienced a blue-screen death (another app) that - on restart - made Firefox again fail to open. Complete delete/purge/reinstall corrected it on one account, but not the other; even after a complete control panel/yada/delete, it demanded a reboot. Repeatedly. And wouldn't recognize the reboots at all.

I'm getting close to the end.

more options

Try: 1. Right click the Firefox shortcut 2. Select Properties 3. Select Compatibility 4. Check the "Run this program in compatibility mode for:" . 5. Select "Windows XP (Service Pack 3)" under the drop-down list. 6. Click OK and try launching Firefox again. It worked for me, although it changes the look.