so i just set up my my 2nd screen and now im not able to launch CSS or any other steam game.
both screens are the same resolution and Hz.
i also launch the game on my main screen.

my PC specs:

windows Vista 64bit
gfx card: Nvidia GTS 450
ram 4gb
quad core 3.0ghz

i hope any of you knows this problem and knows a fix :s

edit: i can launch non-steam games through steam just not actual steam games

oh wow i feel so stupid right now T.T
anyways thanks allot!!

yes it worked

Finally back to css, couldn't play for 2 whole hours O.o

sure proof way is to turn ingame overlay off its only thing that worked for me so far :]