I'm here to willingly help, if I could. What are the symptoms of your problem? Can you watch the clips you want to split/join? If you do so, probably you only need to pick the right program to cut/join. For example Easy Video Splitter not works well with all kind of files for me, especially wmv, often freezes, but Easy Video Joiner is fine. Boilsoft Video Splitter does the splitting well, but don't shows the right colors for wmvs (only ca. 4 strange negative colors), it's hard to navigate in the movie, so I've picked Xilisoft Video Editor for wmvs, which seems to be fine in every aspect... Life is a bitch, especially at video editing. So there is no absolute solution. Yes, too much codecs might be a problem too. Have you installed many codec packs beside K-Lite? K-Lite is a good pack, a little bit too much for me in itself, but rarely cause problems. If you're unable to bear the fight with the conflicting codecs (or programs that use codecs), you sould try to uninstall the packs. But remember: splitting/joining is not a codec problem in first approach. It's the problem of the splitting/joining program, mostly. The programs should manage the files without any codecs, if the movie format characteristics was coded to the program itself. But yes, sometimes the programs read out that characteristics from the codecs. Or sometimes it uses another, older codecs for the cutting/joining than the active, newer version, which is being used by the movie player. So, the first question: Can you watch the movies you want to cut/join? What kind of formats are they? wmv? avi? mpg? mov? rm? Oh, for the Angelpotion Definitive codec: I don't know it, I don't have it, I don't need it... I use MPlayer with built-in codecs for MPEG-4 movies.