While it is true that NT does not have concept of drive letters (and current directory for that matter), it does not internally do equivalent of unix mounting,

While it is true that NT does not have concept of drive letters (and current directory for that matter), it does not internally do equivalent of unix mounting, it just presents volumes in predetermined places of directory hierarchy. The fact that large swatches of win32 API are implemented as userspace abstractions is wonderful source of weird windows behavior. For example, changing current directory is not thread safe (not only in the way that you don't know which directory is really current in presence of multiple threads changing it, but SetCurrentDirectory() itself is not an atomic operation)