Need help setting language on WinDVD

Hope someone can help me with this problem.

I’m trying to view a Chinese VCD movie using the InterVideo WinDVD 5. However, when I’m watching the movie, I can hear both Cantonese and Mandarin language at the same time from the PC’s speaker, which is very annoying.

And if I use the headphone, then I can hear one earpiece is in Cantonese only and the other earpiece is in Mandarin only.

So my question is, how do I set my WinDVD so that I only
hear it in either Cantonese or Mandarin only.

Really appreciate your help.

Mike