After downloading the extensions you shouldn't have any problems. Try deleting version.txt from your game files.Okay so I fixed the .dll problem BUT I am still getting an ogre exception that is stopping the game from getting past the black box of loadiness. (I downloaded the alternative link to fix the .dll problem)
Your computer doesn't like Direct3D9 Rendering system.It won't even pop up the start up screen to let me select the render system.
You can either try and reinstall, or try running the OpenGL Rendering system instead.
You can change the rendering system on start up, after the blackbox disapears.
What does your update.log say? If anything goes weird, That will have something to say most likely