All the software in the Google Pack is free. Some programs may offer paid versions that provide additional features or ongoing updates, but you're never obligated to install the paid versions.
Several programs, including the virus detection software available through the Google Pack, include subscriptions for automatic updates. These updates enable such programs to identify and remove new threats, and are free to our users. Although a program may offer the option to upgrade to a paid version, you can continue to use the free version offered through Google Pack, as long as you have it installed.