Software programs, such as an operating system or other application programs, are automatically customized to a specific user(s) based on data corresponding to the specific user(s) that is maintained in a user information store. In one embodiment, the information store is a unified store that is accessible by multiple programs including the operating system. Thus, new information or information changes can be made available to multiple programs by the user adding (or changing) the information only once. In another embodiment, the operating system image to be installed on a computer is pre-populated with user-specific information at the factory. The user-specific information can be integrated into the operating system at the factory or alternatively upon an initial boot of the computer by the user.