Try to make the folder named "CON","AUX" or "NUL"....Not created !!Not only this, but also some folder names like PRN, AUX, CLOCK$, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, LPT9 and more are not created.

Why we are not able to Create Folder "CON"..Reason behind this :

We can not create folder "CON","AUX" or "NUL" because these are reserved keywords used by DOS. so if u r allowed to create such folders, there will be an ambiguity in where to write data when the data is supposed to go to the specified devices. In other words, if I want to print something, internally what windows does is -- it will write the data to the folder prn (virtually u can call it a folder, I mean prn, con, etc are virtual folders in device level). So if we are able to create con folder, windows will get confused where to write the data, to virtual con folder or real one.That's why these folders are restricted by DOS for creation.

Now I am giving the solution for this.Just follow the simple steps and you will be able to create such name folders in few seconds.....

Method 1 :

Steps ::

1)Make a new folder.
2)Rename folder from the right click option.
3)Press alt and press 255...
 press 255 frm the right side of the keyboard i.e, Num pad where only numbers are given.....
4)Now write "con" or "CON" and then press enter.....yuppie !! It is created....
You'll see a con folder in ur pc.
You can also delete it easily.

Method 2 :
Steps::

1)Open Command Prompt(Start->run->cmd)
2)Type this command(If you want to create a folder in D drive):
md \\.\d:\con
This will create con folder in D Drive.
3)To Remove the folder type this command
rd \\.\d:\con
This will remove con folder from D Drive