If you are using Umbraco or Orchard for a CMS run website, you will unfortunately discover that they run under the Default Website of your PC. This prevents you from using this for multiple sites. There is a workaround however, and it uses apps built into XP Pro.
To create another website, run the below commands under the command window.
C:\Inetpub\AdminScripts> cscript.exe adsutil.vbs create_vserv W3SVC/2
C:\Inetpub\AdminScripts> cscript.exe adsutil.vbs copy W3SVC/1 W3SVC/2
2 is the Id of the new website. Further websites obviously need a new number. When you see your new website under IIS manager, you need to stop the other websites before running the one you want to.
To delete a website you created yourself, just run the below command.
C:\Inetpub\AdminScripts> cscript.exe adsutil.vbs delete W3SVC/2