http://blogs.msdn.com/oldnewthing/ar.../22/55388.aspx
Scroll down a couple of pages.

CON was (or still is) the console where you interact with the command interpreter.

wow I never new that. Really interesting there is such a big quirk in windows... although not that suprising.

really? lemme try that... oh yeah... its a reserve word for control panel it says...

You can refer this:

How To: Create a CON Folder in Windows Vista or in XP

Read this amazing fact:-

“An Indian discovered that nobody can’t create a FOLDER anywhere named as “con“. This is something pretty cool….and unbelievable . At Microsoft the whole Team, including Bill Gates, couldn’t answer why this happened!!!”

In Microsoft’s Windows operating systems like Windows XP or in Vista we cant create folders with names CON, PRN, AUX, CLOCK$, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9 directly from GUI. This is because, DOS device names are reserved words, and cannot be used as folder or file names.

Okay do one thing press Alt and type 255 from NUM keys and then tried to write any one of name from given list : CON, PRN, AUX, CLOCK$, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9 ; and see it happened .
or still confused okay best trick is
1. run>cmd>ok
2. press md\\.\\c:\<dir path>\con
< dir path > is path for making this folder
3. press Enter to make it.

Try to del it .
Is it not deleated , why!!?

KumarUtkarsh@<DaniWEB.com>

From early DOS command interpreter. We used copy con c:\path bla bla..to enter data or to make it appear that data was coming from "console"

May be 'con' or other words like that only appear to Windows GUI version...

nothing fascinating...
in DOS shell 'copy con' is a command for making a file.
like: "copy con new.txt"
and 'copy' is for copying a folder
so, it is reserved command by its creators to avoid ambiguity.