i had the same problem at first. figured it out one second ago.
go to "start" -> "run" and type in: cmd
a command box pops up, now change the directory to your drawringapp folder. do so with: cd C:desktopdrawringapp (or whereever you unzipped it)
now you can type in: drawringsapp -image saturn.tga
works for me, except my screen resolution is far too low (1024x768 max). dont now if its the easiest way. im a newbie too 8)