ASP.NET 4.0 application not accessible when hosted on IIS 6 + Windows 7

1) I have an ASP.NET 4.0 app hosted in IIS 5.0 on an XP machine. The 'Directory security' for this application in IIS is a) Allow anonymous users b) Allow IIS to use password c) Integrated windows authentication.

This application is accessible by browsers in the other PC's in the same network, and things are fine.

2) However, when i host the same application in IIS 6 on a Windows 7 syst开发者_如何学Goem, with the same IIS settings as above , except that there is no checkbox for 'Allow IIS to use password', it is only accessible in local PC, but not on browsers of other PC's of the local network. The browser gives the standard 'The page cannot be displayed error'.

Is there anything different in IIS 6 security ? Why would this app, which is accessible by the network when hosted on XP and IIS 5, not be accessible when hosted on IIS 6 on Windows 7 ?

Thanks, Rao