We're sorry to hear that your Firefox seems to be crashing when you open it. Please perform the following steps to give us a crash report ID that helps us find out more about the cause of the crash.

1. Press the following shortcut to get a Run window: [Windows] + [R]. This should bring up a window that contains a text field.
2. In that text field, enter %APPDATA% and press Enter. An explorer window should open.
3. From that explorer window, double-click on the Mozilla folder, then double-click on Firefox and then on Crash reports. Double-click on submitted.
4. Now, you should see a list of files that contain reports. Go to View > Arrange Icons by > Modified to get the most recent files at the top of the window.
5. Open the most recent 5 files with a text editor and copy the IDs.
6. Paste each ID into the reply window on the forums.

Thanks in advance!

You can find more information and troubleshooting steps in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

Here are the last 5 crash IDs

bp-2903e297-acd2-4566-ba2b-250702120731
bp-3f3672ed-dd2a-4723-b11c-ef3172120731
bp-0d1bbbfe-ca0a-42b5-aea8-7bb1d2120731
bp-e856b43c-12f0-45d1-a5b3-78aaa2120731
bp-ba9676d4-fb85-448c-9f98-de0f32120731

Unfortunately, I got a little impatient and uninstalled FF after posting and reinstalled. Next startup failed, now FF works in safe mode, works sometimes until crashes so the problem seems a little different to crashes immediately all the time. But perhaps the logs might show something. thanks for helping so fast. Darcy

Try the Firefox Safe Mode to see how it works there. The Safe Mode is a troubleshooting mode, which disables most add-ons.

• You can open the Firefox 4.0+ Safe Mode by holding the Shift key when you use the Firefox desktop or Start menu shortcut.
• Or use the Help menu item and click on the Restart with Add-ons Disabled... menu item while Firefox is running.

Don't select anything right now, just use "Continue in Safe Mode." To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before using the Firefox shortcut (without the Shift key) to open it again. If it is good in the Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one.

Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.

When you figure out what's causing your issues, please let us know. It might help other users who have the same problem.

Also note: The crash ID unfortunately does not indicate where exactly the crash occurs. So, we'll try some general troubleshooting steps.

All crash reports look different although some seem to indicate a problem with the JIT compiler (disabled in Safe mode).

See also:

• http://kb.mozillazine.org/Firefox_crashes
• https://support.mozilla.org/kb/Firefox+crashes

Hi!

All plugins are up to date, right? Plugin Check

Okay so safe mode prevents the immediate crashing upon start-up. That's a first step. It indicates that one of the add-ons is causing the problem. You'll have to disable all add-ons, then re-enable them one by one, while restarting firefox after each enable in order to see which one is causing the startup crash. Go to Tools -> Add-ons -> Extensions.

As for the flashplayer crashing during your web browsing, that's likely related to Firefox's existing problems with the newest Adobe Flash version. Do you have this one Shockwave Flash 11.3.300.268? You can check by going to Tools -> Add-ons -> Plugins. If so you'll have to downgrade Flash. See here Downgrade Flash

I wonder if this helps?