weecalf, if you download Chrome or firefox using the links methyl provided, just open it up and it will ask do you want to use chrome or firefox as your default browser, click yes, internet explorer can be an icon on your desktop if you don't like either browser you can just go back to IE, personally I prefer Chrome
It is possible to avoid adverts completely, vastly increasing speed, but I hesitate to tell you how as the Ed of this site is not very keen, since its revenue comes from advertising.