OS: Windows XP (Service Pack 2) or Windows Vista (Service Pack 1) Processor: (XP) 2.0 GHz P4 processor or equivalent; (Vista) 2.4 GHz P4 processor or equivalent Memory: (XP) 1 GB; (Vista) 1.5 GB Graphics: 128 MB Video Card with support for Pixel Shader 2.0 Hard Drive: at least 6.5 GB of hard drive space with at least 1 GB additional space for custom content.