I've installed IIS (and every feature/component) on a Vista Home Premium OS and still, during the beginning of the SQL 2005 installation, I get the following warning messages:
1. - IIS Feature Requirement (Warning)
Microsoft Internet Information Services (IIS) is either not installed or is disabled.
IIS is required by some SQL Server features. Without IIS, some SQL Server features will
not be available for installation. To install all SQL Server features, install IIS from Add
or Remove Programs in Control Panel or enable the IIS service through the Control Panel if it
is already installed, and then run SQL Server Setup again. For a list of features that depend on IIS, see Features Supported by Editions of SQL Server in Books Online.
IIS is completely installed and running. I've gone as far as rebooting and stopping/starting the IIS Web Server again and SQL still thinks IIS isn't installed.