Starcraft 2 won't launch

Hey I recently built a computer and everything is fine except Starcraft 2 won't work. I don't know where the disk is but I downloaded it from Batte.net. Anyways when I open Starcraft 2, it says its up to date and the play button appears. When I click that is just disappears and nothing happens. Any help is greatly appreciated

 

Isn't there a repair option somewhere for Blizzard games? Have a look in the program files for it under Starcraft II.

 

Under Starcraft II it seems there are no files at all. Any ideas?

 

Go to your Starcraft II folder. Find a folder called 'mods', inside there should be a file called 'challenges'. Delete that then try the launcher again.