-> Tap ALT key or press F10 to show the Menu Bar

-> go to Tools Menu -> Options -> General -> When Firefox starts : select "Show My Home Page" and click Reset to Default -> click OK

Check and tell if its working.

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

• https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes
• http://kb.mozillazine.org/Preferences_not_saved