We are trying to launch the txt files using above. We want to launch multiple txt files in our application. If we use above code then we end up launching multiple application. Please let me know if there is a way to launch multiple text files in one editor.
Well you need an editor that supports opening multiple files in a single instance.
The code you gave will open the default text editor associated with .txt files on Windows. You should either change the association to a different editor, or find an appropriate editor that you can call from the command line. TextPad will open multiples files, as will many other editors.