Does anyone know a good software/program for combining long video files?

i really need to, my dvd shrink won’t recognise my files in reauthor mode.

ever since i installed nero showtime it changed all my files.

does anyone know a good program? …or how to uninstall nero showtime?

What Video Format are they in?

^^^they are mpeg/IFO/BUP
if u know how to get rid off nero showtime plz tell me someone

You have to completely remove Nero, there isn’t a cretin way to remove just Nero Showtime.