question on opening files

[mdwoade]

I have textpad 5.1.0 used with windows operating system. I know I used to select a file in explorer, and right click. If I chose "textpad", the file would open in a new textpad window, but if I chose "open with" then "textpad" the file would open in existing textpad window. Sometimes I like to open separate instances of textpad, and sometimes I like to open just one instance. I cannot seem to open files in an existing instance of textpad any more, is there a way? I know I can do this from within textpad; I want to do it from windows explorer.