Its amazing how sometimes the littlest features of an operating system, can be very useful. The Snipping Tool is an incredibly useful tool if you only need to capture part of the image on your computer's screen instead of the whole thing.
Most of the time if you want to capture part of the image on your computer's screen you have to use the 'PRT SCN' key, or the Alt+'PRT SCN' key to capture the active window. Then you have to paste the picture in to an image editor to extract the part of the image that you want to use.
When you launch the Snipping Tool the screen will become partially white, with a red cross-hair. All you have to do is click and drag the red square over the area that you want to capture.
The image will then be transfered in to the Snipping Tool application window automatically. Where the image can be copied, marked up, or sent via email to someone. You can also save the image in one of the following image formats: JPG, GIF, PNG or MHT (single HTML file).
To access the Snipping Tool, from the Start menu go under 'All Programs' then Accessories'. From there you should see program in the menu.