I'm trying to capture my videos into DVD, but the source sound is terrible. Is anyone know what softwares can remove background noises & hissing sounds & how to use it?

Thanks for your help.
P.S
I already tried Roxio, but didn't help much. I also have Sound Forge. I heard that it can remove background noise, but I don't know how to use it. Anyone know how???, please show me. Thanks