Prolly cuz if their box won't run AHII, it won't run the other game either.
Posted requirments:
• Pentium III, 600 MHz or above.
• Compatible with Windows 98, 2000, ME, XP.
• 256 MB RAM, 384 recommended for best play.
• DirectX 9.0
• DirectX compatible sound card.
• 32 MB DirectX compatible graphics card with transform lighting.
Last time in a couple of months back with an AMD 1.2 with 512ram and a GeForce 2 card gave me "passable" frame rates. Low twenties in high action/graphic situations.
Same setup in AHII before my new box I was getting 45fps in the tower by tweaking with graphic detail etc. 50 or better flying regardless of envirement. The AHII engine is easier on the box.
If you don't have any juice left in the box, your kinda watching the world go by regardless of your vantage point.