Try to start Firefox with the about:blank page by creating a copy of the current Firefox desktop shortcut and add a space and -url "about:blank" to the target field.

Try to delete the sessionstore.js file in the Firefox profile folder to prevent restoring the crashed session.

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\
• http://kb.mozillazine.org/Profile_folder_-_Firefox

The "AppData" folder in Windows Vista and later Window 7+ versions and the "Application Data" folder in XP/Win2K are hidden folders.

• http://kb.mozillazine.org/Show_hidden_files_and_folders

It still crashes unfortunately.

If you can start Firefox in Safe Mode by holding down the Shift/Options key then you can try to disable hardware acceleration in Firefox.

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

You need to close and restart Firefox after toggling this setting.

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes
• https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

Disabling hardware acceleration seems to fix the issue, thank you. Why would this be the cause of the problem?

You're welcome.

That is quite likely if disabling hardware acceleration did the crashes stop. It is possible that one of the tabs (likely the last one you opened and that got restored automatically) was causing the crash.

You can set the browser.sessionstore.max_resumed_crashes pref to 0 on the about:config page to get the about:sessionrestore page immediately with the first start after a crash has occurred or the Task Manager was used to close Firefox.

• http://kb.mozillazine.org/browser.sessionstore.max_resumed_crashes