When you plug in your LAN plug, you should see some LED lights come on at the connection point.  What color are they and which side of the plug are they lit, and are they blinking or steady?

And no sound sounds like a driver issue.  Or . . . it could be the guy did not connect the speaker correctly.

LOL.  I asked that because I was having the same problem with the LAN port on my Gaming Rig #1, which I posted somewhere else on the tech forums.  The booklet that came with your mobo should tell you what the lights mean.  I think the steady orange light means that you have either 10/100 or 1GB connection.  The green, which should be flickering might mean internet connection.  

I had the same problem until I loaded Windows, then used the CD that came with the mobo to update the drivers.  Oh yeah, the problem was also that I was trying to load Windows XP Media Center Edition, which according to ASUS tech support, is not supported by any of the chipset drivers because they don't support MCE.  And the fuckers don't print that on the fucking box. 

Anyway, the other question I wanted to ask was whether you had configured your internet connection profile thingy in the admin tools section.

The other option is to spend $5 on a LAN card, if you have an extra PCI slot.  I purchased one at Fry's for like $1.99 on sale.  They are usually like $4.50.  You would disable your onboard LAN device and just use the one in the PCI slot.

Hey, why the fuck I didn't ask this before is beyond me, but did you enable the LAN device on your mobo in the BIOS settings?  Check and report back. I'm in computer fixing mode tonight so I'll be waiting for your response.