Instructions
Download 3D Analyze and then double-click on 3D Analyze.exe.
Click on the "Select" button. In the window that appears, navigate to where Crysis.exe is located (it is on your hard drive in the "Program Files" folder inside a folder called "Crysis") and double-click on Crysis.exe. 3D Analyze will know which program you wish to run.
Click the "Run" button. 3D Analyze will launch Crysis and allow you to play it, as if your computer has a better graphics card.