How to automatically close cmd window after batch file execution?

Modify the batch file to START both programs, instead of STARTing one and CALLing another

start C:\Users\Yiwei\Downloads\putty.exe -load "MathCS-labMachine1"
start "" "C:\Program Files (x86)\Xming\Xming.exe" :0 -clipboard -multiwindow

If you run it like this, no CMD window will stay open after starting the program.

You normally end a batch file with a line that just says exit. If you want to make sure the file has run and the DOS window closes after 2 seconds, you can add the lines:

timeout 2 >nul
exit

But the exit command will not work if your batch file opens another window, because while ever the second window is open the old DOS window will also be displayed.

SOLUTION: For example there's a great little free program called BgInfo which will display all the info about your computer. Assuming it's in a directory called C:\BgInfo, to run it from a batch file with the /popup switch and to close the DOS window while it still runs, use:

start "" "C:\BgInfo\BgInfo.exe" /popup
exit

If you want to separate the commands into one command per file, you can do

cmd /c start C:\Users\Yiwei\Downloads\putty.exe -load "MathCS-labMachine1"

and in the other file, you can do

cmd /c start "" "C:\Program Files (x86)\Xming\Xming.exe" :0 -clipboard -multiwindow

The command cmd /c will close the command-prompt window after the exe was run.