@LaughingOtter: It's true that the version of DirectX that comes on the Tron 2.0 CDs was out of date, even then. But that applied to a lot of games released around that time. You can't hold that against Tron 2.0, because it's in no way unique when it comes to that.
Besides, the way DirectX installers are supposed to work is that if you have a newer version of DX: they see that and then do nothing. Your newer version of DX doesn't get replaced by the older one on the disc.
The requirements for the game back in the day were actually pretty mild. 500 Mhz processor, 256 MB RAM, 32 MB video card/chip with T&L. The card/chip didn't even have to be DX9 capable, DX8 would do. You just needed the DX9 software installed, which came on the disc if you didn't already have a newer version. And those specs were already out of date in 2003. I had a 2 GHz processor, 512 MB RAM, and a 128 MB video card and they were pretty commonplace at that time, if perhaps costing a bit more.
The one thing I will grant you: when the final patch was released, at first it required you to own Windows XP which was pretty new at the time. The patch was paid for, in part, by Microsoft. So it was artificially restricted to work on XP only, to try and "encourage" you to update to XP. This was a scummy move on the part of Disney/Buena Vista and Microsoft.