Indeed the extra memory doesn't hurt. I'm also running Wiz8 on W2k, CPU=Athlon 700, RAM=256MB, video=GeForce2MX 64MB. I usually multi-task with Outlook Express, IE and Excel (for my Alchemy mixing list)

All this goes fairly smooth, but when taking a look at the memory usage in Task Manager, Wiz8 is usually using around 140MB of virtual memory. This means that with only 128MB RAM W2k would need to do a lot of swapping.
Oh yes, I'm running the game with DirectX7 at 1024x768x32.