tiko

I have to decide which one to install in my computer windows xp pro or windows 2000 pro and I'll be grateful to receive the answers to my folloing questions:

1. Is it possible to install (have) IIS (Windows information server) in both OS?
2. Which are rge most important differences between them?
3. If you had to choice which one would you prefer?

Thanks in advance and sorry if my questions are kind of silly.