My failed attempt to take a screenshot in Diablo 1

If you all know, I am a big fan of Diablo, specifically Diablo 1 because I haven't played 2 (and its expansions), and of course I didn't play the third one.


I have been playing though it for the third time, and wanted to take a few screenshots of my armor, but I got a weird screenshot when I took one. I know the Diablo game flashed red when I pressed Print Screen, but I didn't know what that meant. And I still don't.