The newest version of windows, Windows 7 now supports portrait mode(vertical) for computer screens.Though most Display drivers support this screen mode transition,in Windows 7 it is available within the OS.This setup will be very useful if you want to read more content in vertical mode where a lot of scrolling will be required otherwise.
Under the Display Settings there is an option for you to flip the computer screen from portrait to landscape mode (and vice-versa) with ease.
