2008-06-19 (updated 2008-11-19)
Minimum:
* Windows 95, 98, NT4 SP5, 2000 or XP
* 233 MHz Pentium CPU
* 32 MB RAM
* 650 MB HD space
* 4X CD-ROM drive

Multiplayer:
* 64 MB RAM (for hosts: 128 MB, 256 MB with more than 4 players)
* 950 MB free HD space