I press enter but nothing happens.

@aztrus could you please share your DXDIAG with us: 

1. Hold down the Windows key and press R on your keyboard.
2. In the Run box that appears type "dxdiag"without the quotes and press OK.
3. If you get a box asking to check if your drivers are digitally signed choose Yes.
4. In the new window that appears, give it a few seconds to complete it's processing then click Save All Information in the bottom right.
5. Save the text file somewhere easily accessible, I'd recommend your desktop!
6. Double click the text file to open it, press CTRL - A to select all of the text then CTRL + C to copy.
7. Go to http://pastebin.com, and use CTRL + V to paste the data into the webpage and click submit 
8. Copy the link and paste it here

Check also if there is a driver update for your videocard available and try to click the Enter button icon on screen. We have a few reports about player who cannot enter the game even after forcing their high speed GPU to support the game. Is the screen switching from fullscreen to windowed mode if you press the key combination ALT+ENTER?

Cheers
Basti