So I made two movies with my web cam, but on the first I forgot to switch the sound to what the computer outputs so I have crappy audio recorded from my web cam, I reset the audio and did it again, only this time the video wasn't as good.

So I was wondering what program I could use to swap the audio of the two (My Windows Movie Maker sucks and crashes every 10 seconds). Also note these are fairly large files if that affects anything.

Thank you in advance!

-The Noob