I would check your sound properties via the control panel. It sounds ( no pun intended lol ) to me that your speakers aren't configured properly. If the setting is at say 7.1 speakers and you have a 2.1 set up it will sound like you have mentioned. To do this go to control panel, Hardware and sound and then click sound. In the box highlight speakers and click configure in the bottom left hand corner, change settings to suit your set up.
As for the software, have you tried checking the websites to see if any updates for Vista are available?

__________________