Minimum OS: Windows XP SP3 Processor: Intel Core 2 Duo @ 2Ghz / AMD Athlon 64 X2 equivalent Memory: 2 GB RAM Hard Disk Space: 6 GB free Video Card: NVIDIA GeForce 8600 / ATI Radeon HD 2600XT (256 MB memory) DirectX®: 9.0 Sound: DirectX Compatible Additional: Initial installation requires one-time internet connection for Steam authentication; software installations required (included with the game) include: STEAM Client, Microsoft Direct X, Visual C++ 2008 Redistributable, Visual C++ 2005 SP1 RedistributableCompatible