Retail Copy

• 1). Locate the icon for Crysis Warhead.
  
  
• 2). Right-click the icon and select "Properties".
  
  
• 3). Locate the command line, then add -DX9 to the end. Click "Apply" to save these changes.
  
  

Steam Copy

• 1). Start Steam and select "My Games"
  
  
• 2). Right-click Crysis Warhead, then select "Properties."
  
  
• 3). Select "Launch Options" from the properties menu, then add -DX9 to the end of the launch options command prompt.