If you just want to rebuild the Web Components Role. The easiest is to do the following
DeActivate Web Conf
DeActivate Web Components
Uninstall IIS
Uninstall Web Conf
Uninstall Web Components
Install IIS
Launch OCS Installer - it will find the missing roles and walk you thu installing them.
This is usually only needed if the Web Components or IIS Metabase becomes damaged or someone has trashed the permissions in IIS.
--geoff