An on-demand software and service access system has a remote processing system or remote service provider accessible via the Internet or other network, and a local system which runs on a user's local device. The remote system has a plurality of different software applications, operating systems, and central data storage means for selective access by authorized users from their local computer via a network or the Internet, as well as a profile manager for providing user registration, user login, and loading of user selected settings and services onto the local system. Usage of the selected software applications is provided on a subscription basis for applications required by users on a daily basis, as well as on a one-time purchase basis, for one time use, for use only for a specific time period, or permanently.