How to check if a IIS directory is virtual directory or not?

Answer 1

Looks like you can use System.DirectoryServices.DirectoryEntries to read the IIS metabase. See here and here.

There is also a metabase.xml you can look at if you use IIS6.

Answer 2

This works for me on XP / IIS5.

adsutil.vbs GET W3SVC/1/ROOT/TestMPIService/KeyType
KeyType                         : (STRING) "IIsWebVirtualDir"

adsutil.vbs GET W3SVC/1/ROOT/aspnet_client/KeyType
KeyType                         : (STRING) "IIsWebDirectory"

More about the adsutil here: http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/d3df4bc9-0954-459a-b5e6-7a8bc462960c.mspx?mfr=true