A screenshot, or screen capture, is an image taken (captured) directly from what is shown on your screens.
Taking a Screenshot
There are a few common ways to take a screenshot.
Games commonly have a key binding for the Print Screen button to capture and store a screenshot of that particular windoow. Usually these screenshots capture only the game's own DirectX rendering, so ISBoxer widgets including Repeater Regions, Click Bars and Video FX will probably not show up in your normal game screenshots. This can be good or bad, depending on whether or not you want the ISBoxer widgets to show up or not. :)
To capture a complete screenshot of all game windows and ISBoxer widgets, we instead use the screen capture function of Windows. Windows has a global key binding for the Print Screen button, which captures an image of your entire desktop, including all of your monitors, to the Windows Clipboard (like selecting Copy). Similarly, Alt + Print Screen will capture an image of just the current window, including any of its border area. Because these images are in the Windows Clipboard instead of saved to disk automatically like the game's screenshots, we need to Paste the image into an image editing program -- Microsoft Paint is sufficient if you do not have an alternative.
As of ISBoxer 40.3.0726.2, the Screenshot Action can be used to conveniently capture either of the above types of screenshots. See HOWTO: Make a custom Screenshot Hotkey for a walkthrough using the Mapped Key Wizard.