Minimum:

OS: Windows 98 / ME / 2000 / XP
Processor: Pentium III 600 MHz or Athlon 600 MHz processor or higher for systems with Windows 98/ME, Pentium III 700 MHz or Athlon 700 MHz processor or higher for systems with Windows 2000 / XP
Memory: 128 MB
Graphics: 3D hardware accelerator card required - 100% DirectX 9.0b compatible 32 MB hardware T&L-capable video card and latest drivers*
DirectX: Version 9.0b (included)
Network:
Storage: 1.4 GB of uncompressed free hard disk space (plus 400 MB for Windows 98/ME swap file, 600 MB for Windows 2000 / XP swap file)
Sound Card: 100% DirectX 9.0b compatible 16-bit sound card and latest drivers
Additional Notes: 100% Windows 98/ME/2000/XP compatible mouse, keyboard and latest drivers

Multi-player Requirements:

Internet (TCP/IP) and LAN (TCP/IP) play supported
Internet play requires 56kbps (or faster) modem and latest drivers
LAN play requires network interface card and latest drivers

Important Notice: *Some 3D accelerator cards with the chipset listed here may not be compatible with the 3D acceleration features utilized by Call of Duty. Please refer to your hardware manufacturer for 100% DirectX 9.0b compatibility.
*Supported Chipsets

All ATI Radeon cards
All nVidia GeForce cards
Matrox Parhelia

Call of Duty achievements