Well, I've got a win98Se system with an AMd 800 Mhz processor, but over 300 MB RAM.
<img src="/ubbthreads/images/graemlins/div.gif" alt="" /> run just fine, but for <img src="/ubbthreads/images/graemlins/beyond.gif" alt="" /> I had to use the minimum of detail etc. within the game. Otherwise it wouldn't run.
What you need in any case is *lots* of free hard disk space !