Most of you may be aware that MS-DOS Device Driver names cannot be used as file names in Windows. As a result, we are unable to name folders as con, aux, nul, etc.
Microsoft MS-DOS had reserved these names for these system device drivers.
CON : Keyboard and display
PRN : System list device, usually a parallel port
AUX : Auxiliary device, usually a serial port
CLOCK$ : System real-time clock
NUL: Bit-bucket device
A:-Z: : Drive letters
COM1 : First serial communications port
LPT1 : First parallel printer port
LPT2 : Second parallel printer port
LPT3 : Third parallel printer port
COM2 : Second serial communications port
COM3 : Third serial communications port
COM4 : Fourth serial communications port
Try to create a file or folder with these names on your Windows desktop and see what happens.
Even today if you try to name a folder using one of these reserved names, you will receive the following error message: The specified device name is invalid.
These restrictions still exist in the NT-based Windows, possibly the reason being to allow compatibility for running 16-bit programs and for command-line based programs. The complete Windows Naming Files, Paths, Namespaces, Conventions can be found here.
Create CON, AUX, NUL folder
While you can use Linux or MS-DOS commands to create the folder names such as “con”, I came across this app Concu which claims to let you create and delete folders with restricted names, in a click. It’s a CNET link so remember to click on the Direct Download Link.
Why does this program exist? Just to make a point that it can be done using a tool, that’s all!
I know, I know this is real old stuff, but this is for those who may not be knowing about it. 😉
Anand Khanse is the Admin of TheWindowsClub.com, a 10-year Microsoft MVP Awardee in Windows (2006-16) & a Windows Insider MVP since then. Please read the entire post & the comments first, create a System Restore Point before making any changes to your system & be careful about any 3rd-party offers while installing freeware.