I have about 50 gigs of AVI files which are 16x9, but do not have the 16x9 flag set. Any suggestions on an easy way to set the flag on all of them?
Thanks

Maybe someone knows of a freeware utility for this, although I don't happen to.

If nothing else, you could import your clips into a 16:9 project within a recent version of most any mainstream NLE application (probably even the 30-day free trial versions, I'd guess). You could then export to 16:9 without further rendering...might have to let it run overnight, but then it would be done. Just need sufficient disk space for it.