Ok so. I didn't find any place where problems could be told, so I decided to talk here.
I have SC2 and downloaded/installed correctly SC2 Beta Launcher. When I click on the launcher, it opens BUT, there's a pop-box appearing saying: Lazylaunch2.exe cannot be found. I have the program in the same folder! It's there! Someone might know what the problem is?
EDIT: I found how I could play. I dragged Lazylauncher2 myself on the Beta Launcher and it worked! By the way, Starcraft 2 is so awesome! ^^