INSTRUCTIONS ON HOW TO USE PRINT SCREEN IN WINDOWS
To do a print screen in windows you have two choices. PRINT SCREEN for the entire screen or ALT PRINT SCREEN for the active window. Now both will make a copy to paste the copy goto PAINT and paste it.
INSTRUCTIONS ON HOW TO USE PAINT
Open Paint by clicking the Start button Picture of the Start button, clicking All Programs, clicking Accessories, and then clicking Paint. Click Edit, and then click Paste.
INSTRUCTIONS ON HOW TO USE PRINT SCREEN IN UBUNTU
In Ubuntu you just press PRINT SCREEN AND THEN save it where ever you need to. For the active window, just select the window and then do a PRINT SCREEN.
INSTRUCTIONS ON HOW TO USE PRINT SCREEN IN MAC OS X
To save PRINT SCREEN hold and release Apple key, shift key and 3 all at the same time. You follow this with a mouse click on the desired screen. You can do a PRINT SCREEN of a selection by holding Apple key, shift key and 4 and then releasing. Next just drag the cursor around selection. In both cases, the file is saved to your desktop