Your best defense against registry viruses is to make sure you do three things that are essential to protecting your computer. First is to always have a firewall up and anti virus software running when you use your computer. This will help stop registry viruses from ever getting in. Second is to not download any program or file that your anti virus senses is malicious or seems malicious to you. This is so difficult because you cannot always tell what is malicious or what is not but be vigilant. The third thing is to back your important personal files every week and make sure you have your copies of the software you have loaded on your computer available in case you have to reload them.