How do I delete mb sound drivers from bios?

Hi,
I haven't been back in awhile. I'm still very happy with my computer that I got about 4 years ago and although I still haven't updated it, it's still working wonderfully with games I want to play. :D
With that said, I am having some issues with my sound devices.  I was having problems unrelated and had to boot from the Windows XP cd to fix the problem...that problem was resolved but it created a new one. A very annoying new one.
My computer now reads two drivers and it gets confused.  So, my sound won't play on the internet or for some games using Steam to activate them.
The sound works everywhere else, though.
I researched and found that I have to uninstall the mb driver...Legacy Audio Drivers..I cannot delete or uninstall the drivers from the device manager because it doesn't give me that option.  Something is amiss with everything and I don't know how to fix it.
The only way I can get my sound to play through my Audio Blast sound card is by going into the Device Manager and uninstalling the Audio Blast driver and then restarting my computer.  The new hardware wizard detects it and reinstalls the driver and everything works. Yay!  But if I shut down my computer without first uninstalling the Audio Blast driver than the sound doesn't work on the internet again and I have to go through the whole procedure of uninstalling and restarting my computer which is becoming a pain in the butt. 
I was told to disable the mb driver or speakers or whatever from bios.  I am a noob with bios. I tried, thought I accomplished it but I didn't do something right because I'm still having the same issue.
Grrrrs. 

So, can someone pleeeeeeease explain to me how to fix this? Either through the bios or whatever else I have to do? I'd so appreciate it.
Thanks in advance.

You don't, your sound drivers are on the os.

try and find the latest drivers for the audio if possible.