单项选择题 After setting up a new computer, a user states that the mouse and keyboard will not work. Whichof the following is the MOST likely reason?（）

单项选择题 Windows XP mode on a Windows 7 Professional machine fails to load. Which of the following isMOST likely the cause?（）

单项选择题 A single office with five computers and a server is an example of which of the following?（）