A Set Top Box or other client/server device including an Internet appliance which runs an application and operates under any of several operating systems. The Set Top Box boots from boot code stored, for example, in a ROM which permits a user to select an operating system and application. The Set Top Box contacts a Master Server and obtains a URL for download of the operating system and application. The URL is contacted and the application and operating system are downloaded. The Set Top Box operates under the operating system to run the application until another application is selected.