Alright, this is just slightly different, but may help others.
Issues: Using Vista Home Edition, thus Cassini WebServer
Using the DotNetNuke Starter Kit or DNN WebSite Sample in the Zip, unzipped into my c:\inetpub\wwwroot\dotnetnuke
NB: In Vista Home Edition, you have limited IIS, so the folder inetpub\wwwroot is still created
Registered the DotNetNuke c:\inetpub\wwwroot\dotnetnuke\Default.aspx on the Cassini Webserver and took note of the port assigned to it e.g. 2252 as against fixing a port number (which you can)
If you browse from the Cassini WebServer, the page opens fine and allows you to finish the rest of your setup, I used Auto Config option.
If you attempt to Login/Register, the page bombs out, IIS giving an error it can't find the page, if you look closely, the Port Number is missing from the http://localhost, if u manually replace it on the bombed url, the page loads.
To make this permanent, either using your SQL Server Management Console, or from your Visual Studio/VWD environment access the database e.g. Database.mdf
Goto PortalAlias Table, Edit, and change the HTTPAlias column to localhost:2252, i.e., you just added :2252 (replace with your cassini webserver chosen port id) you could also change localhost if you have a domain choice change
Save the Database change, make sure its saved.
Your good to go.