There's a number of ways.
1. Use the [PrintScreen] Key.
That takes snapshot of the screen and stores it in the clipboard. You can then paste into any application that will accept graphics, such as Paint, Word, Paintshop Pro, etc. If you are takeing an action shot of a CC game, then you would have to [Alt]+[Tab] out of the Game (minimize), and do the Paste, then switch back to CC. That's not very convenient for continuity.
2. Use a third party application.
There are quite a few. The following all work:
UOSU - Ultima Screen Capture Utility. Is available from our Downloads. Very easy to set up and use. Useful features such as re-mapping the 'Snapshot' key, and using timed 'shutters', where a snapshot is taken automatically at intervals you sepcify. A ragne of saved formats. A very popular utlity, and free.
Paintshop Pro. A popular Graphics editing application. Started life as shareware that fitted on 1 floppy disk. It requires moderate effort to get used to, but very functional and full of features. It has a screen capture facility. Not convenient for taking snapshots uninterrupted (you still have to switch to Paintshop Pro to save the image and switch back to CC if you want to do multiple captures).
HyperSnap. This costs a few bucks, but is the best screen capture application I use. All the features of UOSU are there, but a lot more besides.
There are more...
I reckon that you take Linebacker's advice, and use UOSU. It's worth the very little effort it takes to get it up and running.
[font=Arial]SILENCE! when you speak to an Officer![size=17]
[font=Verdana]What goes around, comes around....