Minimum: OS: Windows 7 / Vista / XP Processor: 3.0 GHz P4, Dual Core 2.0 (or higher) or AMD64X2 (or higher) Memory: 1GB XP / 2 Vista GB RAM Graphics: Video card must be 128 MB or more and should be a DirectX 9-compatible with support for Pixel Shader 2.0b (ATI Radeon X800 or higher / NVIDIA GeForce 7600 or higher / Intel HD Graphics 2000 or higher). Storage: 4 GB available space Additional Notes: Requires a Steam version of Portal 2 Installed