Hi Rob Moorhead,
Thank for getting back to us.
Here is the Sitefinity System Requirements
page. As you can see from there we do support IIS 6.0, SQL Server Express, and we do support Windows Server 2003. There should be between your IIS version and the database platform that you are using as long as it is from one of the supported one.
The installation guide has a chapter on how to configure IIS, and it discusses the configuration of IIS 6.0. There should be no other additional settings to the IIS. Make sure that the ASP.NET worker process has full control over the ~/App_Data/
directory of this site. As it says in the installation guide you should make sure that ASPNET account has database owner permissions to the database that you are using. This is also discussed in the installation guide.
the Telerik team