Minimum: OS:Windows Vista Processor:2 GHz Dual Core Memory:2 GB RAM Graphics:NVIDIA GeForce 8600 GT / ATI Radeon HD 2600 XT or greater DirectX®:9.0 Hard Drive:20 GB HD space Sound:DirectX Compatible Other Requirements:Broadband Internet connection Additional:Initial installation requires one-time internet connection for Steam authentication; software installations required (included with the game) include Steam Client, Visual C++ 2008 Redistributable, DirectX and Microsoft.NET 4.