I think IIS / PWS are the servers bundled with Microsoft win Cd's which can be configured for serving pages.
IIS-Internet Information Server ( In add remove components)
PWS-Personel Web server - Older win 98 systems.
Linux has a plenty.
Also try apache,sql,PHP.
But u need to run ur comp 24x7 for that matter dude
i think a broadband leased line connection should be used for the webserver as it can provide access to everyone in the world. Otherwise you will find that only a few people are able to access the webserver(due to firewall problems). Check it out with the connection provider. Also in terms of softwares you can use Apache.