Windows XP: 1.5 GHz processor Windows Vista: 2.4 GHz processor Note: Older Celeron processors, from before 2004, are below the minimum requirements. Windows XP: 256 MB RAM Windows Vista: 512 MB RAM Windows Vista SP1 or Windows XP SP2 Operating System. At least 3 GB of additional hard drive space Keyboard and 100% Microsoft compatible mouse Direct X certified sound card DirectX is required and the game will install/update it if necessary. Installation/update of DirectX is not optional.