I think you might have not installed the sound system properly and this is the most correct fault on a vista proccesor. You might have connected the wires loose.
Or read the user manual of the new product.
The only thing i can say is go to the main voice controller and put the voice up which can be accesed by:
1) Start and search windows mobility and click the program, put the volume up.
2) or double click the speaker thingy at the bottom-right of your screen to access the main voice controller and put your volume up.
3) or try finding a volume controller in control panel.
hope this helps
ICT NERD
March 2009