If You try to create folder named “
con”, “
prn”, “
nul” “
com1″ “
com2″ “
lpt1″ etc. in windows ? 
NO its Not Possible....
NOTE :- [If You Are Think About We Can Also Type By Using "ALTR+0160" But Its giving space and also its Invalid] 
NO because when create a new folder and try to  rename it to any  specified names, you know what  happens! In Windows XP the folder name automatically changes back to  “
New Folder” no matter you try any number of times. Where as in Windows  Vista/7 when you try to rename the file you get an error message “The  specified device name is invalid”.
What is the reason for this? Simple, these names represent the  internal devices and hence we cannot create folders with the above  names.
YES because it is still possible to create these folders using the 
command prompt. Here’s the instructions to create it.
Step To Creat con Folder
Step 1:- Go to command prompt
 Type in prompt (FOR EG. TO CREATE CON FOLDER IN 
E: DRIVE)
C:\>md \\.\e:\con
  
 NOTE: “con” can be replaced by any other names such as “prn”, “nul” “com1″ “com2″ “lpt1″ etc. 
Step 2 :- To delete the folder use the following command
NOTE: The folder can only be deleted from the command prompt.You cannot remove it by right-click delete.
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