2008-06-03 (updated 2010-06-13)
Minimum:
* MS-DOS 5.0
* 486 CPU
* 256 color VGA GPU
* 8 MB RAM
* 3 MB free HD space
* 2x CD-ROM drive
* MS-compatible mouse

The game box also mentions Win95 as potential platform, but this is only because Win95 was still quite backwards compatible with DOS 5.0.