Windows reserves certain names for built-in processes. If you were to use
these names for things other than those intended by Windows, then some
features would not work. Hence, you cannot name files or folders CON, PRN,
AUX, CLOCK$, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9,
LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, or LPT9. For other
restrictions, see:
http://msdn.microsoft.com/en-us/library/aa578688.aspx
