A reoccurring post I keep seeing on the newsgroups is people asking if they can upgrade the version of IIS on operating systems such as Windows XP.
Since windows 2000 every version of the operating system has had its own version of IIS. For example:
Windows 2000: IIS 5Windows XP: IIS 5.1Windows server 2003: IIS 6
Both Windows 2000 and Windows XP have a very similar architecture, but windows XP is limited to only 1 website.
You cannot run IIS 6 on Windows XP as IIS 6 only ships with Windows server 2003. If you require the functionality of IIS 6 you must install a copy of Windows Server 2003.
I hope this makes things a little clearer :-)