Why You Can't Name A File CON In Windows

Tom Scott0 HN recommenders · 2020–2026
7.8M views · explainer · evergreen · Uploaded 2020-04-20

Tom Scott explains why Windows does not let you name a file CON, tracing the reserved device names back to backwards compatibility with DOS.

Linked as a relevant explainer in threads about Windows quirks and reserved names.

Watch on YouTube

4 comments from Hacker News

@gresrun2020 · in “Macintosh Y2020”

Excel also has a deliberate bug where it thinks 1900 is a leap year because they wanted compatibility with Lotus 123, where the bug was actually a bug! [0] [0] [VIDEO]

@irshadshalu2020 · in “macOS Big Sur Preview”

can't speak about the very recent updates, but windows have been consistent and adamant on keeping the backward compatibility. they still use reserved file names for io devices so that 30+ year old printers can still work, and you can still open a 2000s doc file in office 365. (I'm looking at you Apple, who made many of the 32 bit apps I loved useless) relevant video: [VIDEO] (Tom Scott: Why you can't use CON as filename in windows)

@RajT882023 · in “The .zip TLD sucks and it needs to be immediately revoked”

It's wild to me some of the things I never knew, even though I've been using Windows or DOS for probably 35 years. For example, I recently learned you can't name a file CON. Try it. Somehow over all those decades, I've never tried to do this until Tom Scott made a video about it: [VIDEO]

@cardboard99262026 · in “Coreutils for Windows”

Don't think this will ever happen, especially since this is Microsoft you are talking about [0] [0] [VIDEO]