It is possible to get print screen software for free. In fact, both Windows and Mac OS X operating systems include free print screen applications. Alternatively, install the free version of Fraps to print the screen in full screen applications.
To print the screen on a Windows computer, hold down the Windows key and press the PrtScn key. This automatically takes a screenshot and saves it in the Pictures folder.
Alternatively, use Snipping Tool to save only a portion of the screen. Type Snipping Tool in the search box on the taskbar or in the Start menu, and click Snipping Tool from the results. Once the application opens, click New and mark the part of the screen to capture. As Snipping Tool does not save screenshots automatically, make sure to save before closing the application.
If using a Mac computer, print the screen by holding down the Command and Shift keys and pressing 3. To take a screenshot of a part of the screen, hold down the Command and Shift keys and press 4, then mark the area to capture. In both cases, Mac OS X automatically saves the screenshot to the desktop.
As neither operating systems is capable of printing the screen when a full screen application is running, third-party software is necessary. Download the free version of Fraps from its website. With Fraps running in the background, press F10 to print the screen. Fraps saves the screenshot in a folder called Screenshot in the directory it's installed to.