audio editing

[Jomo2]

Hi,
I purchased this instructional cd which plays just fine on my computer. There is a very slight hum which is hardly noticeable. I recently converted this windows media audio/video file to a dvd file (if that is what it's called) and burned a dvd. The video on the dvd is just fine but the humming noise is much louder and quite annoying.
I was actually able to isolate the audio from the dvd file and cleaned up the sound with audition. I then ran this file through windows media encoder to shrink the size. This all went well! My problem is I do not know how to put the video (which I never separated from the audio, that is the only video I have is the windows media audio/video file and the dvd I made from this wm a/v file) and the audio together.
I was hoping that someone could tell me how to proceed from where I'm at or even tell me an entirely new method.
Keep in mind that I am very very new at this!
Steve

[drfsupercenter]

OK, you don't want Windows Media Audio.

Save it as a wave file in Audition, and then download the program BeSweet and BeLight GUI. (I cannot link here since I'm at school)
Open BeLight, and select "mp2" and give it the wav file. This should make a DVD audio file for you.

As far as muxing it goes, get a free trial of TMPGEnc, and open MPEG Tools (in the File menu).
Select "Simple multiplex", for the video give it the VOB file and for audio, select the mp2 you just made.

This should give you a DVD file with the audio you want.