Hi dwennon, Thank you for your question. Unfortunately it is hard to give support steps without an crash reports. However since Firefox is not starting I would recommend trying to start it in Safe Mode:

• Diagnose Firefox issues using Troubleshoot Mode

You can also try to start Firefox with a new profile from the cmd.exe:

1. Open a cmd.exe or put cmd.exe in the Start menu
2. Paste this:

"C:\Program Files (x86)\Mozilla Firefox\firefox.exe" -p

1. Hit enter and when you see the manager pop up, click create new profile. Enter the name and open Firefox

If then it continues to crash please submit the crash report ids: 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 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.

Looking forward to hearing from you :-)

If you can't get Firefox to open, you will have to do this the hard way. Open the file browser on your computer. Depending on your system, you need to find this folder; C:\Users\=<User Name>=\AppData\Roaming\Mozilla\Firefox Once you are there, look for a folder called Crash Reports. Inside are two folders; submitted and pending. Go into each. Copy the last 5 File Names in each folder. Remember, the last 5. Check the date/time. Post all the information in the reply box below. Forgot to add, with each file name, include the date and time created.