ActiveDirectorySiteCollection.Remove Method (ActiveDirectorySite)
Removes the first occurrence of an object in this collection that is identical to the specified ActiveDirectorySite object.
Assembly: System.DirectoryServices (in System.DirectoryServices.dll)
A call to the underlying directory service resulted in an error.
The object does not exist in the collection.
site is null.
The ActiveDirectorySite object has not yet been saved in the Active Directory Domain Services store.
Available since 2.0