You should be able to install the original Matrix version from your original CD or original download if you didn't get the CD, then click the update button on the opening screen.
If you don't have either, then I think you can still download the game by logging in to the Matrix site with your member name and login. Not sure where the link is from there, but I'm sure I can find it if you can't.
If you don't remember your login at the matrix site and you don't have your original install, then you'll need to contact them. I've heard they're pretty helpful with stuff like this.
Found the link, but you'll need your username and password:
http://www.matrixgames.com/products/318/...ign.Series
Pretty sure you need the original game installed first, but I'm not positive.
Resolve then, that on this very ground, with small flags waving and tinny blasts on tiny trumpets, we shall meet the enemy, and not only may he be ours, he may be us. --Walt Kelly