Windows 10 MSG command mystery

Solution 1:

You are apparently using on all computers the Home version. This version does not include the MSG command. The command is only available in Windows versions starting from Pro.

As a side-remark, tested on Windows Enterprise, even the old "net send" command still exists in that version.

By all reports, trying to transplant msg.exe from higher Windows versions to Home does not work, so there is no easy workaround.

You can however write your own.

By using the free psexec you can execute code on remote computers that creates a pop-up message.

See the post Show a popup/message box from a Windows batch file for a few ideas.

The niftiest ones I found were:

• mshta.exe, the runtime engine for Windows .hta HTML applications, accepts a general URL as command line argument, including a javascript: protocol URL. So you could issue an alert with a timeout of 10 seconds this way:

  mshta "javascript:var sh=new ActiveXObject( 'WScript.Shell' ); sh.Popup( 'Message!', 10, 'Title!', 64 );close()"
  

• Using a VBScript file and call it using CScript, with something like the following in a .vbs file:

  Set objArgs = WScript.Arguments
  messageText = objArgs(0)
  MsgBox messageText
  

Solution 2:

Running MSG /? on the Win 10 box said that MSG was not recognized as a command

We bought a new PC for a new office; it of course has Windows 10 (Home) on it.

Home editions of Windows do not include msg

Source Msg - Windows CMD - SS64.com

What other commands need to have the same kind of magic done so that they work from a normal command prompt?

That question is "too broad".

Solution 3:

The MSG program is only available on Pro or Enterprise versions of Windows.
It's main intend is to notify users on a terminal server or similar stuff. It requires certain rights normally only available to administrators (normal user can be given the right to use it) meaning its main intend is to be used by windows Administrators to notify users about an shutdown, problem, etc.

The subfolder inside of WinSxS is from an Windows Update. Microsoft calls this folder "Component Store" and more info about it can be found in this article:
https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/manage-the-component-store
I was able to find the same folder with msg.exe on my system. Looking at it, it doesn't seem like its an valid .exe file at all, its starts with "DCS" when looking at it in an hex editor but should start with "MZ" if its an executable file. I was not able to find any documentation about this "DCS" header.

Alternatives would be simply sending an mail and opening it in your web mail client if both computers have internet access. Windows 7 and 10 also both come with an feature to offer assistance to other people, it can be opened by starting msra.exe If that method does not work you could use other remote management tools like Teamviewer. Teamviewer has an option to use LAN only connections meaning no internet is required to use it on a local LAN.

Solution 4:

As detailed here and here, you need both msg.exe (to go in C:\Windows\System32)

• C:\Windows\WinSxS\amd64_microsoft-windows-t..commandlinetoolsmqq_31bf3856ad364e35_10.0.18362.1_none_fb86e15d293d8d62\msg.exe

and msg.exe.mui (to go in C:\Windows\System32\en-US)

• C:\Windows\WinSxS\amd64_microsoft-windows-t..etoolsmqq.resources_31bf3856ad364e35_10.0.18362.1_en-us_f257f72e582e10e5\msg.exe.mui

However, first they need to be decompressed (shameless self-promotion) using SXSEXP:

> sxsexp64.exe msg.exe expand\msg.exe
Processing target path  msg.exe
msg.exe => expand\msg.exe
File size               12602 bytes

DCS_HEADER found.

 NumberOfBlocks         1
 UncompressedFileSize   26112

DCS_BLOCK #1
 Block->CompressedBlockSize     0000312A
 Block->DecompressedBlockSize   00006600
Operation Successful

> sxsexp64.exe msg.exe.mui expand\msg.exe.mui
Processing target path  msg.exe.mui
msg.exe.mui => expand\msg.exe.mui
File size               2150 bytes

DCS_HEADER found.

 NumberOfBlocks         1
 UncompressedFileSize   7680

DCS_BLOCK #1
 Block->CompressedBlockSize     00000856
 Block->DecompressedBlockSize   00001E00
Operation Successful

These decompressed files are what need to be copied to C:\Windows\System32 and C:\Windows\System32\en-US respectively to use MSG.