I'm using Switch to convert .ts mpeg files off my Humax PVR to mp3, to transfer mp3's onto my mp3 player, to timeshift radio programmes. It works fine on my PC, but the same software installation of Switch when installed on my laptop (which doesn't have an internet connection) doesn't work, saying invalid file. Both are running XPSP2. Obviously I must have some other software installed on my PC, (that I haven't got on my laptop) that enables Switch to convert the .ts files. Any suggestions as to what my laptop is missing, software wise?