Windows "Internet Information Services" missing?

Hi - I am trying to install a piece of medical diagnostic software (which works great from boot camp, but would prefer to run it via parallels), and I get an error during installation at the end where it indicates it requires Internet Information Server 4.0 or higher for configuring it's IIS Virtual Roots. In searching the MS site, it appears this is a feature built into Windows, including XP. MS' instructions for installing if not already present is to go to Control Panel -> Add/Remove Programs -> Add/Remove Windows Components... from here, simply select the box Internet Information Services. this component is missing from Virtual Desktop, whereas in my other Windows XP installations (even from the same disk) it is present. Any ideas how to restore this?

thanks for any ideas