A method and system within a data processing system for executing a program under one of a number of mutually exclusive operating systems are disclosed. The data processing system includes a nonvolatile mass storage device, a volatile memory, and a processor. According to the present invention, a program which executes under a second operating system is invoked while the processor is executing a first operating system. In response to invocation of the program, the data processing system is forced to a quiescent state. A state of the first operating system is then determined from contents of the volatile memory and stored within either the volatile memory or the nonvolatile mass storage device. In response to storage of the state of the first operating system, at least a portion of the second operating system is automatically loaded into the volatile memory. Thereafter, the program is executed under the second operating system, wherein interchange between mutually incompatible operating systems within a single data processing system is efficiently accomplished. In a preferred embodiment of the present invention, the method of the present invention is embodied within a computer program product for causing a data processing system to perform the foregoing steps.