Block the IP address? Why? If you do that, then no one on the internet will know where you are!
Are you responding to a pop-up telling you that everyone can see your IP address and that you should hide it? If so, then ignore that.
Your IP address has to be seen - when you log on to the internet, (or any network) and request data, then the responding computer needs to know where it is to return it to.
Get a firewall, anti-virus prog, and a spyware checker and after that you will be ok.