Back in the days of DOS, the PrintScrn key used to print the screen. But
in all versions of Windows, this works differently, and the name of the
key is now an anachronism.
To use the key, press it to capture an image of the entire screen, or
press alt-PrintScrn to capture an image of the active window. Either one
captures the image to the Windows clipboard. Once it's in the clipboard
you can paste (Ctrl-V) it into any application that supports graphics
(Windows Paint, other graphics programs, even your favorite word
processor). You can edit or add to the image as you wish, then print it.
This ability to manipulate the image in a program before printing it is an
improvement over the original DOS method of just printing it. But if you'd
like that old facility back, there are several third-party
freeware/shareware programs that can do this, such as PrintKey2000
(
http://www.sharewarejunkies.com/00zwd2/printkey2000.htm).