Automatic installation activation selection for hosted services

Automatic installation and/or activation selection for hosted services is provided. A set-up user interface for users to sign up and activate their membership with a hosted service may prompt an activation module to analyze a computing environment of a requesting user to determine if a client application associated with the hosted service is pre-installed or not. If the client application is pre-installed, the user may be provided a control such as a button to activate the client application and begin using the hosted service. If the client application is not pre-installed, the activation module may determine which version of the client application is proper for the computing environment (e.g., operating system, operating system version, device, and similar parameters) and where it can be downloaded from. The activation module may then present the user with a link to the location for downloading and optionally installing the client application automatically.