OS SWITCHING SYSTEM

PURPOSE:To shorten the OS switching time and to restart the operation of an OS from the interrupted point by preserving plural various OSs in the main storage and the auxiliary storage of one computer to switch them. CONSTITUTION:An OS selecting means which presents usable OSs to a user and allows the user to select the OS to be operated, an OS preserving means 2 which preserves the OS operated at present from an OS execution area into an Os preservation area 13 and updates an OS list, and an OS load means 3 which loads the OS list to the OS execution area to update it are provided. An OS continuous execution means 4 is provided which reads out preserved contents of the OS execution area indicated by the register preservation address of the loaded OS list to set them to registers and continuously executes the selected OS. Thus, the switching time of plural OSs preserved on the main storage and the auxiliary storage is shortened, and the OS whose operation is interrupted is continuously restarted from the interrupted point.