Here's a suggestion, download the latest version of Firefox and save it on your desktop, now uninstall your current FF. Install the new version then get Adblock plus from the FF ad-ons site and install that.
Set FF to ditch all history, cookies etc on closure, make the opening page "blank" and re-set your homepage to what you want. Good luck.
By the way if you want to download music a very good site is:
www.mp3lemon.org this is not a bit torrent site, their range of music is brilliant, and it's free. The only downside is that if you want a whole album you generally have to download a track at a time.