HELP just reinstalled xp and having audio problems...

I have just put a fresh install on an xp machine. I am using onboard sound, which was working fine before reinstall. I installed the realtek audio drivers from my gigabyte cd (which worked fine on my last install...), but I also installed the windows azalia hd sound drivers...I can't remember if I installed those from the gigabyte insallation cd last time or had just installed the realtek drivers. In any case, sound plays through at least windows media center 11, through netflix movie viewer (a combo with silverlight and windows media player) and through vlc media center, but all the regular clicks and pings and such of windows itself don't play and no sound from flash movies or from applets such as npr player.

What's going on? I've checked to see if my speakers (logitech z-5500's) needed drivers...they don't. I've checked the master volume and it's on and not on mute. Initially, I could open the realtek hd audio control panel, but I can't seem to now. Even when I could open it, when I ran an audio test, no audio.

Thanks in advance for any help. I really appreciate it!

Also, when you reinstall, you should be able to put in your cd, and actually tell it you have a disc when trying to reinstall, and then have it search that for drivers, or you can manually pick the driver from the cd.