Instructions
Close any open programs or apps prior to launching "Call of Duty 4." Other open programs use your computer's resources, which "CoD4" potentially could use to deliver a better frame rate.
Launch "Call of Duty 4" and access the options menu, then the graphics menu. These are all the in-game options that affect frames per second.
Disable "Shadows," "Soften Smoke Edges" and "Specular Maps." While you'll still see shadows and smoke, the edges of both will appear less defined. Disabling "Specular Maps" lowers the detail and lighting quality of items, clothing and characters.
Lower the screen resolution under the "Video Mode" option. This reduces graphics quality but improves frames per second. Turning off "Anti Aliasing" and "Vertical Sync" produces similar trade-offs between quality and performance.
Disable "Dynamic Lights," "Depth of Field" and "Bullet Holes." Start the game and determine whether "Call of Duty 4" plays at a higher frame rate now. If not, consider disabling or lowering even more of the graphics options. If that doesn't help, your computer's hardware might not be powerful enough to play the game.