Problems start of Batman: Arkham Asylum

[Astarothell]

Hello guys, I bought Batman: Arkham Asylum by steam ... took forever to download (lousy third world of broadband 300kb).
However when I play, I put the original serial and a msg appears: Press start to begin and esc to exit. But after press start, nothing happens and the game does not start. Ja took the serial, I put again, rebooted, I pray angry and nothing game work. Someone had similar problem with steam?

My configuration is:
Atholon 64 X2 5200
6.00 GB
HD4850 512MB
Win7 64-RC

Ps: There was no error in the installation. Until the screen with the options "play", "settings", "view readme" and "exit" appears, but when play tells nothing happens.
I even did the following, open the task manager of windows and followed the process of the game. What is the process simply closes without explanation ...

Ps²: Pardon my mistakes because I'm terrible in English