How to execute a command via command-line and wait for it to be done

Use the Process.WaitForExit Method:

 public void runCmd()
 {
    String command = @"/k java -jar myJava.jar";
    ProcessStartInfo cmdsi = new ProcessStartInfo("cmd.exe");
    cmdsi.Arguments = command;
    Process cmd = Process.Start(cmdsi);
    cmd.WaitForExit();    
 }
.
.
.
 runCmd();        
 MessageBox.Show("This Should popup only when runCmd() finishes");