Attention

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.As a variable can’t be named as keyword so as the folder.When parsing a reference to a file or folder, Windows correctly checks for the case in which a single DOS device name is used in the path, and treats it as invalid. But in computers there is nothing is Impossible. We can create folders with these names in Microsoft Windows Vista or in XP.If you try to make a folder named “CON” (case insensitive)in Windows Vista or XP renames it back to what it was. So creating a new folder with the name “CON” just renames it to “New Folder”.The bug seems like a variable that got treated as a string or vice-versa. Trying to create the folder from a cmd prompt failed with an error “The directory name is invalid.”.This also works when you try to create a file called “CON”, or “CON.” “.CON” shows up the way it should.Moreover, if you try to use a reserved name to name a file such as a Notepad or Microsoft Word document you will generally receive an error message.