Hi,
I’ve download a film but it’s split into 2 avi files, is there anyway of convert the two files into 1? 
windows movie maker will do it
and there are many other programs too, the list is endles, go here
http://www.videohelp.com/tools?s=108#108
Virtual dub is another
the best is camstasia studio
you can even make it smaller if you need to’
Your reason for doing this could make a huge difference in what to recommend. If you just want to past them together (why?), that’s a whole lot different from, say, trying to fit them onto a single disk, which would involve shrinking, and maybe converting. OTOH, maybe you don’t need to join them to achieve whatever you’re trying to do.