We’ve always been able to click on PrntScrn to take a snapshot of the full screen. Unlike the old MS-DOS days, where PrntScrn actually sent the screen to the printer, as of the first version of Windows, it copied the screen to the Windows Clipboard.
From the Clipboard, you could paste it into a Word document, a WordPad document, a spreadsheet, into Paint (the Windows image editor in Accessories), or into many other programs. From those, you could actually print the image.
Windows also has had the Alt-PrntScrn combination, which does the same things except with an image of only the active window.
Windows 7 has a really nice tool for taking a snapshot of a user-specified portion of the screen. It’s called the Snipping Tool.
Like Paint, it’s found in the Accessories sub-directory of All Programs. Left-click on the Windows Orb, then hover over (or click) All Programs, the hover over (or click) Accessories. Now you can left-click on the Snipping Tool, as shown below.
In the image below, you can see the Snipping Tool dialog box. Notice that the entire screen has been overlaid by a soft white mask.
The next step is to decide where you want to start your image — left-click at that point and drag the crosshair pointer to the opposite corner of the portion that you want in the image you are creating.
As you can see below, as you drag the selection tool, the white mask is removed from the area to be in the resulting image.
After selecting the image with the Snipping Tool pointer, release the mouse button.
That will result in the Snipping Tool dialog box showing up again, this time with an image it in. That image has already been copied to the Windows Clipboard, so you can immediately paste it into WordPad, Word, your graphics editor, or whatever.
The Tools item on the Snipping Tool menu bar includes the Pen (Red, Blue, Black or Custom), the Highlighter, the Eraser, and an Options selection.