Probably been asked before

[dimpy]

If a video is broken up into avi.001, avi.002 etc. How do I append them into one file so I can play it?

 

[Rhinosaur]

HJSplit.
Open it, select the first file, hit join. It will automatically find (as long as they're in the same folder) and join all subsequent files leaving you with the full .avi.