Could you install it on your XP OS? You never said which you've tried it on. Your page you linked to shows it should run on XP. Your XP isn't 64 bit too, is it?
Whether it'll actually run on 32 bit XP will tell you whether it'll work or not. I tried finding information on the programming architecture of it, but could find nada. If the installer is 16 bit, it should install on 32 bit XP. It will not install on your Vista 64 bit, because it probably is a 16 bit installer. If it's a 16 bit program itself, your Vista will obviously not run it no matter what you do, unless you grab an emulator of some sort.
If you can install it on another machine, and copy whatever files it writes, you may be able to get it to work. You will definitely need to install it on something that will take it. Looking at my SC2000 CDs contents, there are a few more folders that get installed (and thus, files) that aren't present on the CD. You'll more than likely need to get the registry files as well that it installs. Run regedit, then do a search (check all boxes) for maxis, simant (or sim ant) to find any files in the registry. Take note of where they are, as well as copy them with the rest of the files previously mentioned. Stick them in your new registry, making sure that the path in the registry is the same as the machine you installed it on. Create whatever folders you may need to in the proper place in the registry. Also, make sure the paths are still correct when you do paste the new .reg file. It does no good to install the directory at C:\ on your XP machine, then try putting the directory files in C:\Program Files on the Vista machine. Your .reg files will still be pointing to C:\.
Does that all make sense?