Time for another one of my, please-don’t-forget-this-again posts.
I was running some code today that was calling the ADSI (Active Directory Service Interfaces)IIS://LocalHost/W3SVC. However I was getting access denied. After trying every admin user on this earthly realm I decided that access denied was a red-herring. I then realised that ADSI is an IIS6 only feature and not part of IIS7. Once I enabled the IIS6 compatibility features the code started working again.