XCOM Enemy Within

OS : Windows Vista or later
Processor : 2 GHz Dual Core (Core 2 Duo 2.4 GHz or Athlon X2 2.7 GHz) CPU
Memory : 2 GB RAM
Graphics : 256 MB Video Memory NVIDIA GeForce 8600 GT / ATI Radeon HD 2600 XT or greater
Hard Drive : 20 GB available space
Sound Card : DirectX compatible sound card

 OS : Windows 7
Processor : 2.4 GHz Quad Core CPU
Memory : 4 GB RAM
Graphics : 512MB Video Memory ATI Radeon HD 3000 Series/NVIDIA GeForce 9000 Series or greater
Hard Drive : 20 GB available space
Sound Card : DirectX compatible sound card