This is the how the directory should be setup:
C:\Program Files (x86)\Electronic Arts\Crytek\Crysis 2
These files should be in the Crysis 2 directory:
bin32
gamecrysis2
Engine
patch
system.cfg
Make sure you installed the Crysis 2 SDK into the same directory as Crysis 2, so there should also be the following files:
Bin64
Editor
editor.cfg
If those files are not there, then you didn't install the Crysis 2 SDK in the right place.