Comments on: Forbidden file and folder names on Windows

By: Jason

Jason — Tue, 09 Mar 2010 08:20:30 +0000

Or just use Cygwin to bypass this silly restriction, especially if you’re a Linux user.

By: David

David — Thu, 04 Mar 2010 22:37:30 +0000

There might be a use for this. If you create the folder from the command line as mentioned above, you will now have a seemingly undeleteable, unmovable, unrenameable folder. This can be useful if you don’t want an inexperienced user messing with your files.

Also, if you want to create a file (not folder) with the name con, follow these steps:
1. Create the file as you normally would
2. From the command line, type the following, making sure to replace the path, as well as use the correct file extension:
rename “\\.\c:\[path to file]” “con.txt”
You now have a file with a forbidden name!

By: me

me — Thu, 19 Nov 2009 15:37:30 +0000

I was creating a tex folder “aux” and it did not work. I thought a program is blocking the path until I found this page.

By: Thor Whalen

Thor Whalen — Sun, 08 Nov 2009 15:30:23 +0000

Usefulness? Indeed! Imagine having a program that produces files, automatically choosing the name according to some useful scheme. Well bang! You will probably (if you’re processing a lot of data) stumble on a hard to catch funny bug.

For example, if you’re dealling with IATAs, you’ll hit a problem as soon as you’re processing PRN (Pristina International Airport), CON (Concord Municipal Airport), etc.
True story.

Or say your files are taken from emails… I assure you, you’ll get a few con.rad@gmail.com, prn.me@whatever.org etc. And you’re screwed.

Sigh! Windows!

By: Allewar

Allewar — Tue, 14 Apr 2009 00:09:18 +0000

I spent a whole afternoon trying to find the problem with copying files from a Mac computer to a windows file server. After many hours searching in files permissions, windows security preferences, and all sorts of sharing options, I narrowed the problem to some specific folders named ‘aux’. Then I googled it and found this page.

By: Alin Faur

Alin Faur — Mon, 26 Mar 2007 14:13:53 +0000

Actually, the 255 ASCII code corresponds to a space, so the name won’t be “AUX”, but ” AUX”, which is different from the one wanted, so it is logic that it will allow you to do it.
In fact, it’s the same as if you tiped “ZAUX” or “_AUX”, which means that it’s not included in the list mentioned above

By: Ritesh Aswal

Ritesh Aswal — Wed, 21 Mar 2007 08:05:41 +0000

It will work

By: Ritesh Aswal

Ritesh Aswal — Wed, 21 Mar 2007 08:04:54 +0000

just right click on rename and then press alt+255
Give the name
CON
PRN
AUX
CLOCK$ (NT and older)
NUL
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9
LPT1
LPT2
LPT3
LPT4
LPT5
LPT6
LPT7
LPT8
LPT9