ok I've looked and I believe your mobo has a Nforce chipset.
Are the drivers you've got on the CD Nforce drivers? ifso you can uninstall them from the "add remove programs" applet in the control panel. try looking for them there anyway if they're not Nforce.
When you reinstall use the latest Nforce driver from the nvidia website. http://www.nvidia.com/content/drivers/drivers.asp
Nforce 4 series AMD.
Alternatively you could get them via ABIT ABIT
the Abit link is to version 6.67 and the Nvidia link is to version 6.86. this is probably just because ABIT haven't updated their link but it might be because they havent tested compatabilty past version 6.67... Take your pick.
Edit: Just to be clear Nforce drivers are a bundle for the whole chipset, including the network interface. I recommend you remove *all* your current chipset drivers and replace with the recent Nforce ones.