It's sad to hear you're about to leave Mozilla Firefox if you can't fix this issue. You might have installed some software which has set MSN as your homepage. I see you blocked MSN already, but have you tried to set an other website as your homepage? (like Google) You can do this on the upper right corner (The 3 bars) --> preferences --> general, and take a look at the Startup options. Make sure you selected "Show my homepage" at the first option, and use the URL of the homepage you prefer on the second option. If this is confusing you, make sure you copy the settings which are selected on the screen shot i added to this reply. If non of this works, try to use the option "Restore to Default" (This option is also on the screen shot on the bottom right) I hope this answered your question, if not, please reply.