Command "docker" not recognized in windows powershell

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I am using Windows Powershell (on windows 10). I am also using the latest version 2.3.0.5 of docker desktop. When I type "docker version" in powershell the command is not recognized. The error message reads "Der angegebenen Datei ist keine Anwendung zugeordnet." (English: No application is assigned to the specified file). When I instead include the file extension and type "docker.exe version" the command can be executed. The interesting thing is that "docker version" works in a cmd window, but for some reason not in powershell. The extension ".exe" is contained in the windows environment variable PATHEXT.

What could be the reason that it doesn't work in powershell?

PS: I had an old version of docker installed before. There everything worked fine. Then I updated to the newest version. After that I couldn't use my existing docker containers anymore. So I uninstalled the old version and installed version 2.3.0.5. Since then I have this issue.

docker powershell
1 Answers

tl;dr:

  • Run Get-Command -All docker | ForEach-Object Path

  • Among the file paths returned, remove those that do not end in *.exe (use Remove-Item).

The likeliest explanation is that, in one of the directories in your system's path ($env:PATH) that comes before the one in which docker.exe is located, contains another file whose base name is docker:

  • Either: It is an extension-less file literally and fully named docker [This is what it the problem turned out to be] .

    • PowerShell unexpectedly tries to execute this extension-less file, because it considers it executable, despite - by definition - not having an extension designated as executable via the PATHEXT environment variable ($env:PATHEXT).[1]

      • This would explain cmd.exe's different behavior, because it sensibly never considers an extension-less file executable.

    • Presumably, the uninstallation of the old Docker version removed the original docker.exe, but left an extension-less docker file in the same directory behind (possibly a Unix shell script).

  • Or: It does have an extension (other than *.exe), which:

    • refers to a file that isn't directly executable and needs an interpreter - a separate executable - in order to be executed

    • and that extension is listed in the PATHEXT environment variable

    • and the association between the filename extension (e.g., .py) and the (information about the) associated interpreter is (now) missing, possibly as a result of having uninstalled the older Docker version.

[1] In fact, PowerShell unexpectedly considers any filename extension executable - see GitHub issue #12632.
However, for those extensions not listed in PATHEXT, execution via the path only works if you include the filename extension in a file-name-only call (e.g., executing file.txt opens a file by that name located in the first folder in the path that has such a file in the associated editor). With an extension-less file, there is obviously no extension to include, which is why confusion with an *.exe file of the same base name is possible (unless you invoke with .exe); if both such files reside in the same directory in the path, the *.exe file takes precedence, but if the extension-less file is in a different directory listed earlier in the path, it takes precedence.

user_453750
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