There should be a PrtSc button on your computer (Print screen) Or prntscrn w/e it's called just look for a combination of letters along those lines.
1. press it whenever you want to take a screen shot.
2. Open up an MSpaint file
3. Open up the file menu and click Paste.
Voila! screenshot! Without an annoying 3rd party program that wants you to buy it every 45 minutes. Or takes up unwanted disc space if you DL'ed the torrent.