Well there are required systems, recommended systems, and then there's the one you want.
- Required systems CAN do the job but it'll be the worst quality and take it's time.
- Recommended systems usually can take advantage of some or all of the neat-O effects the game has to offer (like EAX audio for Civ.IV) and can do so at a a playable rate
- The one you want can do everything better than the one you have:/
This game doesn't run from the disc AFAIK; it just needs it to authenticate your ownership so it comes down to your system. If you're between 1 and 2, then it might take a while I'd imagine. A faster PC would proly help. Try to minimize your background progs as they can have an impact (they do with me).
For your reference My.System > Recommended.System took ~1min load to Title Menu and ~1min reload save.