If you have recently bought a LED-backlit display laptop or if you are using an old CRT, chances are that the default Windows colour, brightness and contrast settings are not accurate and make your favorite photographs and movies look different and most times, just plain bad. The colours you see on your screen varies widely depending on your monitor, graphics cards settings, lighting and more, yet most people use the same default Windows colour profile.
Fortunately Windows 7 provides a Display Colour Calibration Wizard that helps you ensure that colours are represented accurately on your screen and everything looks crisp and sharp. Click Start (Press Win Key) and type dccw in the "Search programs and files" box to start the Display Colour Calibration Wizard. Alternatively you can go to Control Panel > All Control Panel Items > Display and click on "Calibrate Colour" from the left pane of the window.