The registry in your computer is where all of the commands that allow your computer to function are kept. Needless to say that most viruses in the world focus their attention on the registry of your computer and that has made registry virus removal a big business for anti virus companies. The problem is that registry virus removal is a very complicated thing because each time you add a program, or change a function, on your computer you wind up changing the registry and after a while salvaging that registry could be almost impossible.