According to the official Call of Duty 4: Modern Warfare Steam Page , the technical specifications required to run the game are minimal: Minimum Requirements Recommended Specifications Intel Pentium 4 2.4 GHz Go to product viewer dialog for this item. or AMD Athlon 2800+ Intel Core 2 Duo or equivalent Memory (RAM) 512 MB RAM (768 MB for Vista) 1 GB RAM (2 GB for modern OS) Storage Space 8 GB available hard drive space 8 GB + extra space for mods Graphics Card NVIDIA GeForce 6600 Go to product viewer dialog for this item. ATI Radeon 9800 Pro Go to product viewer dialog for this item. NVIDIA GeForce 7800 Go to product viewer dialog for this item. ATI Radeon X1800 Go to product viewer dialog for this item. Understanding the Terms: DVD, ISO, and Repacks