Ctrl + F5. Go to the DOS game folder and find the capture folder.
Personally, Print Screen (Prt Scr Sys Rq Button on the top rightish side of the Keyboard) on full screen mode, and paste it in MS Paint. Save picture as Jpeg file. Its a bigger picture in comparison.
Thanks. I'll go try it out now.
Edit: It worked.
Do you know how to record videos, as well?