In order for you to play Hearts of Iron III: Semper Fi on Windows with minimal graphics settings, your computer must meet the following requirements
OS *:
Windows XP/Vista/7
Processor (CPU):
Intel Pentium IV 2.4 GHz or AMD 3500+ (quad core)
Memory (RAM):
2Gb RAM
DirectX®:
DirectX 9.0c or better
Hard Drive:
2GB HDD space
Sound:
DirectX-Compatible soundcard
Video:
GeForce 8800 or ATI Radeon X1900 videocard
Contoller Support:
3-button mouse, keyboard and speakers