While we are on the subject, I would like to mention some software that I have found to be very valuable. It's called "HostsMan" and can be found here: abelhadigital.com
It will allow you to block a lot of the nasty advertising and malware sites out there. You can update it from 3 different content providers and it will delete duplicate entries in your hosts file.
For those who don`t know, the computer looks at the hosts file first for an internet address before looking it up on the internet. (dumbed down a bit for ya). HostsMan will point the computer to itself when looking up addresses for advertising sites or malware sites. So when you are loading up a web page the computer sees itself when being pointed to malware sites. You will get a message in the web page that the information has been blocked. No more advertisements or going to malware sites by mistake!!
And it`s free too. Gotta love that.