Change Windows Screen Upside down

Ctrl + Alt + Down, Keys, Black key board keys

I'm not a software geek but last night i wrongly hit ctrl + alt + down (instead of ctrl + alt + Del). Oops my computer screen went upside down, Actually i was playing a game called Tarzan( not so long..just for 4 + hours). So i thought because of the game only my screen went upside down. After a Google travel only i found the  real reason(I m a dumbest web guy..) and i fixed it. Its not a big driver installation or software update, Just did the wrong click(ctrl + alt + down ) again and the problem solved.
But I'm gonna  play with this trick.. My friends are really dumb than me.. so they surely get scared.. My new scar tactic.. I should grown up huh?.

That's how i Google :
How to change windows (windows 7,Windows vista)screen upside down?
Why my Windows screen turned upside down?
Turn your monitor upside down
Why my desktop turned upside down?