Hi,
Use the tasklist.exe to get the PID of cmd.exe. Then kill the PID using taskkill.exe. These two you need to run from the systemexec function available from LabVIEW.
Generally if you are running command prompt from VI, you can configure to close it once the task is finished. If it is an external program, call the tasklist.exe from another command prompt using System Exec.vi. It will list the running process in spread sheet format. Search for cmd.exe and get the PID (Process ID) for the cmd.exe. Then once the PID is known, use the taskkill.exe and pass both exe name and PID name to kill the running process. http://www.windowsnetworking.com/kb...sklistPUlistlistsactivetasksandprocesses.html and http://www.computerhope.com/taskkill.htm explains the output.