Patent 7272799 was granted and assigned to Hitachi on September, 2007 by the United States Patent and Trademark Office.
A user interface function for a virtual machine system based on a server or a PC is provided only by applying software without using SVP or the like. A control virtual machine is provided for controlling a virtual machine control screen which is displayed for defining virtual machines and instructing operations to the virtual machines. A virtual machine control program exclusively displays either a screen for each virtual machine or the virtual machine control screen in response to a screen switching instruction from an input device.