Hello there, babjeck. Welcome to SevenForums!
Ok, let's see.
1) Please, do not mess with the registry if you don't know what you're doing or if you're not experienced enough. (a little mistake on the registry could mean serious damage on the OS)
2) Are you trying to install it via Windows Update?
3) Do you own a Laptop or Desktop? and please fill in your system specs so we can help you easily.