Windows has a useful utility which allows you to captures a screen shot of anything on your desktop.
Start > Search for 'Snip'
Use snipping tool to capture a screen shot of any object on your screen, and then annotate (add notes), save, or share the image.
Snipping Tool is available only in the Home Premium, Professional, Ultimate, and Enterprise editions of Windows 7.
You can capture any of the following types of snips:
Free-form snip: draw a free-form shape around an object.
Rectangular snip: drag the cursor around an object to form a rectangle.
Window snip: select a window, such as a browser window or dialog box, that you want to capture.
Full-screen snip: capture the entire screen.
After you capture a snip, it is automatically copied to the clipboard and the mark-up window.
From the mark-up window, you can annotate, save, or share the snip.
For more information, see here.
