Hit the "Print Screen/ Sys Rq" button on your key board. This will take a Screen grab, of whats on your screen.
Ctrl+V to paste it onto a blank document in a program such as PhotoShop, or even Paint.
This should do it.
"Your weapons are no match for ours! People of Mars, surrender!"
"Um, this isn't Mars. This is Earth."
"Earth? Earth-with-nuclear-weapons Earth?"
[long pause] "Friend!!"