The problem with it is that when I go to install Norton Antivirus 2007 onto it I cant press ok to install it because the Ok button is at the bottom of the terms of agreement and my computer screen cant see below start bar.
I haven't got a cause or cure for your problem but advise that you should quit while you're ahead. Installing NAV may not be considered a good idea. See
here for an earlier discussion.
I recommend AVG, the free version, with a good firewall such as Zone Alarm or Comodo, again free versions.
Good luck