I'm not really comfortable editing the registry but I'll back it up and give it a go! I have Norton from when I bought the computer around 6 years ago, although I've never used it. I have a McAfee firewall which comes with AOL and also the Microsoft Windows Defender. The settings for these are to allow the Internet Explorer though.

EDIT: I've read the guide and I'm a little confused on how to back up the whole registry!