* Windows 2000/XP * DirectX 9 * 1GHz Pentium III or higher * Video card with VRAM 64MB or above * 2GB of hard disk space * 256MB or more of system RAM * Keyboard, mouse, 4 button gamepads recommended.
more detail Hard disk space for Expansion
* RBO - about 1,40 GB + 150MB for save files. * Ex1 - about 450 MB + 260 MB for save files. * Ex2 - about 470 MB + 65 MB for save files. * Ex3 - about 320 MB + 65 MB for save files.
Saving more replays will increase the requirement. You should also keep some space for Windows swap file.