Create a new profile as a test to check if your current profile is causing the problems. See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

Profile Backup and Restore

• http://kb.mozillazine.org/Profile_backup
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Thanks for your response. I've tried it and it hasn't made a difference. I can start Firefox in safe mode but not in normal.

Try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"

If it works in Safe Mode and in normal mode with all extensions (Firefox/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)

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

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 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.

Crash ID: bp-5f71232c-2ba3-4053-ab4d-5c8932130915

Crash ID: bp-43fdc5d5-d24b-412c-96b0-9a9822130915
Crash ID: bp-74ec717a-d06b-4d5d-acd5-ce7662130915
Crash ID: bp-a2d691c6-f7c9-41aa-83c0-a73b92130915
Crash ID: bp-abf0962e-9f38-441f-9ee5-7970e2130915

Thanks :)

See if you can locate the program that the bitguard-dll file belongs to and uninstall this program.

• http://windowfdb.com/q.php?q=bitguard-dll-c-programdata-bitguard-2-6-1673-238-c16c1ccb-7046-4e5c-ct
• https://crash-stats.mozilla.com/report/index/5f71232c-2ba3-4053-ab4d-5c8932130915

This could also be a problem with Trusteer Rapport

• http://www.trusteer.com/support/rapport-installation-links
• http://www.trusteer.com/support/en/report-problem
• http://kb.mozillazine.org/Firefox_crashes#Trusteer_Rapport

Try to update or uninstall and reinstall Trusteer Rapport and if that doesn't help then disable/stop the program for now.

• Start Menu > Programs > Trusteer Rapport > Stop Rapport

It worked! Thank you so much :)