You can change the screen resolution in Windows Control Panel. As a shortcut to screen settings, right click an empty spot on Windows Desktop and select Screen resolution from the popup menu. Changing the screen resolution can be helpful when adjusting the image in the external monitor or projector. For the sharpest image in flat display panels and video projectors, use the default resolution. At lower resolutions the image is often a little blurry even though objects such as icons seem bigger.
Watch a video on changing screen resolution in Windows 7
Näytön resoluution vaihtaminen