Before you begin developing your web service, you need to decide how you’re going host it. You have several choices: ASP.NET and .NET Remoting are the easiest ones to choose, and I’ll be focusing on ASP.NET in these examples, because it’s the option that gives you the most flexibility.
If you choose to serve your web services with ASP.NET, you need to be sure you have a web server capable of serving ASP.NET pages. IIS, the web server that ships with all Windows NT and Windows Server installations, will do just fine. However, if you’re running on Windows XP personal workstation, you don’t have a web server.Describing Web Services