I believe all of us had moments when we wanted to take a quick screenshot of something but we had no special tools installed or we didn't know exactly how to do it.
In Windows XP, the easiest way to take a screenshot was to press the Print-Screen key and then paste it in Paint. If you wanted to edit the picture and save only a part of the screen you had to lose more time. Paint is very OK for basic tasks but, if you want to do more, you really need a better tool. That means spending money on better software or loosing some time searching for a free or open-source tool.
In Windows Vista, taking a quick screenshot is more fun than ever. That's because Windows Vista includes a very cool tool called the Snipping Tool, designed only for this task.
To find it, go to Start -> All Programs -> Accessories -> Snipping Tool. Alternatively, you can type the word "snip" in the start menu search box. The first result should be the Snipping Tool.
When you start it, you will see the Snipping Tool in the middle of your screen while the rest of your desktop will be covered by a transparent white cover and will seem "disabled". That means the tool is in "screenshot mode". Press the Cancel button and everything will get back to "normal".
The Snipping Tool has four capture modes: Free-form Snip, Rectangular Snip, Window Snip and Full-Screen Snip. They are rather self-explanatory.
When you select Free-form Snip, a small scissor will appear on the screen and with it you can select any parts of the screen.
The Rectangular Snip mode will allow you to quickly draw a rectangle on the screen and capture everything inside it.
In the Window Snip mode you just have to select a window with the mouse and the Snipping Tool will take a screenshot of it. The Full-Screen mode is even more "easy". You just select this mode and the Snipping Tool will capture your desktop and it will automatically exclude itself from the screenshot.
After you have selected the capture mode that you prefer click on New. After you took the screenshot, the result will appear in a new window of the Snipping Tool.
As you can see, now you have a few options at your disposal. You can Save, Copy, E-mail or Edit your screenshot. You can use the pen, choose its color and draw something or you can use the highlighter. If you select the eraser you can use it just like an Undo option and remove what you have drawn or highlighted.
After you took your screenshot and edited it as you wanted, all you have left is to press the Save button, type the name of the file, select its location and the format.
Source Site: Windows Vista for Beginners - Windows Vista tutorials
Source Article: Snipping Tool - taking screenshots is more fun than ever