For complicated reasons, I have been forced to make an identical copy of cmd.exe and rename it to cmd-2.exe, which I put a shortcut to in the Taskbar. The reason is purely to have them "grouped" in different "taskbar groups", and nothing else.
Sometimes, I forget about this, and to open a new cmd.exe, I simply middle-click that Taskbar icon to open a new cmd.exe. Then I type a command such as "dir", and then it spits out a bunch of nonsense, including:
DNS bad key.
This only happens if I accidentally use the cmd-2.exe. Not if I open the "real" cmd.exe. So it's not a "practical" problem.
However, I wonder why that message is ever printed at all. It's apparently failing to do some kind of DNS lookup or something? Why is DNS involved at all with me typing "dir" to list files in my local computer? I have no network set up, no "cloud drives", nothing like that whatsoever. It scares me that (apparently) there are DNS queries being made when I type "dir".
Or maybe "DNS bad key" refers to something completely unrelated to the Domain Name System? I don't know what a "bad key" would even be in that context...