Miscellaneous File System Notes
Windows XP adds several new features to NTFS from Windows NT 4 NTFS: Encrypting File System (EFS), Volume Mount Points, and Sparse File Support.
One of the interesting new features is Volume Mount Points – the ability to mount a new drive under an existing drive, instead of using a drive letter. For example, you might install a new DVD drive and use volume mount points to mount it at C:\DVD versus the D: drive.