A consumer device is presented that utilizes a system and method for downloading from a network server the run time image of the device's operating system and/or application program. As such, the amount of Flash memory required to store the operating system may be greatly reduced, which also reduces the cost associated with such Flash memory. Since the run time image is downloaded from a network server, the image can be updated at the server for bug fixes and feature enhancements. For devices operating in audio/video distribution, additional security is provided to maintain the digital rights management of the A/V content. This security is provided through a combination of hardware and software security features including ROM in the CPU or board mounted Flash memory with an unwritable section. Further, each boot load program checks the digital signature of the program it is loading before that program is allowed to execute.