If you want to set Google as your home page go to www.google.com, then open up Option > General and there you should see something that says "Homepage" and click the button that says Use Current Page. That should set Google as your home page when you open up Firefox it will load Google!

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window.

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