How can I execute a Windows command line in background?

This is a little late but I just ran across this question while searching for the answer myself and I found this:

START /B program

which, on Windows, is the closest to the Linux command:

program &

From the console HELP system:

C:\>HELP START

Starts a separate window to run a specified program or command.

START ["title"] [/D path] [/I] [/MIN] [/MAX] [/SEPARATE | /SHARED]
      [/LOW | /NORMAL | /HIGH | /REALTIME | /ABOVENORMAL | /BELOWNORMAL]
      [/NODE <NUMA node>] [/AFFINITY <hex affinity mask>] [/WAIT] [/B]
      [command/program] [parameters]

    "title"     Title to display in window title bar.
    path        Starting directory.
    B           Start application without creating a new window. The
                application has ^C handling ignored. Unless the application
                enables ^C processing, ^Break is the only way to interrupt
                the application.

One problem I saw with it is that you have more than one program writing to the console window, it gets a little confusing and jumbled.

To make it not interact with the user, you can redirect the output to a file:

START /B program > somefile.txt

I suspect you mean: Run something in the background and get the command line back immediately with the launched program continuing.

START "" program

Which is the Unix equivalent of

program &

Your question is pretty vague, but there is a post on ServerFault which may contain the information you need. The answer there describes how to run a batch file window hidden:

You could run it silently using a Windows Script file instead. The Run Method allows you running a script in invisible mode. Create a .vbs file like this one

Dim WinScriptHost
Set WinScriptHost = CreateObject("WScript.Shell")
WinScriptHost.Run Chr(34) & "C:\Scheduled Jobs\mybat.bat" & Chr(34), 0
Set WinScriptHost = Nothing

and schedule it. The second argument in this example sets the window style. 0 means "hide the window."

START /MIN program 

the above one is pretty closer with its Unix counterpart program &