print screen puts the image on your clipboard ( live temporary memory ) , and isnt written to the disk until you "paste" from the clipboard to a picture file or other object.
So hit print screen , and then open your paint program or photoshop and paste the image onto a blank, then save.
anytime you printscreen it overwrites and replaces wjhatever was on the clipboard.

"The victorious win the battle, then go out to fight ... while the defeated go out to fight, then try to win the battle.   -SunTzu
"The only difference between a capitalist and a communist is that the communist hates competition!" -Circuit

my highest is ~11 secs