"Internet Information Services" are only available on Widows XP professional and not any other version. On the professional it is set to be off by default. control panel>Admin. tools>Internet information services
The rest should be intuitive but wouldn't hurt to Google for the exact procedure, especially safety wise.
Does anyone know what M$ got rid of PWS? An upgrade to Professional not only seems like overkill but as I recall, I can't upgrade from a person to a pro version, correct? Two completely different architectures I believe? Sounds like a lot of work just to setup a dev environment.
Does the IIS replicator work well? Does it support .net or just older ASP/COM?