Abstract: The Microsoft NTFS implementation has a backwards compatibility with older 16 bit applications. These apps could allow attackers to bypass access restrictions for longer file names. So the security recommendation for hardening an Microsoft Exchange environment is often to disable that.
Disabling the NTFS 8.3 implementation is quite easy and can controlled by the following reg key:
Windows Registry Editor Version 5.00
Once done a server reboot must be performed.
Existing files using the short name format will still be available to 32-bit programs, but all files created after this change is implemented will be unavailable to older 16-bit programs.