You may try AVS Video Editor which has many great functions

You may try AVS Video Editor which has many great functions. The features in the official site are below:
1. Direct Transfer to iPod, PSP, Mobiles and Other Portable Players
2. Supports Virtually ALL Video Formats
3. Burn Movie DVDs
4. Capture and Edit Video from External Devices
5. Edit Video and Enhance Your Movies
6. Create Slide Shows
7. Make Perfect Audio for Your Video Editing Tasks
8. Scene Detection
9. Convenient Video Editing Tools and Interface
if u had NERO installed preferably ver 8. U could use NERO VISION. just add the movies u want and burn immediately if you dont want to edit anything.

but if the volume of the video is quite low. you can just right click on the added video and see the properties. you should see there audio adjuster. try 150% (it's what i use usually).

you can even add several movies if u want... its all there and its fun to learn by urself, really. BUt should u need a fast assistance.. just say so then.