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. On the keyboard, press [Windows] The image "Windows key" does not exist. + [R]. This should bring up a Run window that contains a text field.
2. In that text field, type %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 with bp- 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.

The crash reports would help us in giving you an individual diagnosis, but if these are nearly instant startup crashes, let me mention something that is "going around" in case you have this problem:

Firefox is crashing within seconds of startup if you have either of the Applian Technologies programs Freecorder or Replay Media Catcher in combination with Norton security software (and possibly some other security software).

If you have either of those Applian programs and it isn't essential, try uninstalling it and then restarting Windows to ensure that none of its components are left running.

Will Firefox start normally after that?

(If you prefer not to uninstall the program, another user said he used msconfig to prevent FlvSrvc.exe from running at startup and that fixed it. See: https://support.mozilla.org/questions/1086722#answer-789197)

Disabling flvsrvc.exe solves the problem

FF 41 works now

thanks for your help

bill