When Tom said "check the about menu", he meant this:

On the Empeg's main menu, on its actual screen, using its faceplate buttons, go into the main menu and select ABOUT. That's five clicks to the right of the PLAYLISTS menu.

When that menu comes up, press the right-arrow button to scroll down so that you can see the ethernet ip address. For example, mine looks like ETH0 IP: 192.168.0.69

Next, on the computer that you're using to try to connect to the empeg, get its IP address as well. Use the Windows command prompt to do an IPCONFIG. For your "Local Area Connection" ethernet card, you should see an IPV4 address. What is it? Do the first three sets of digits match? Mine says 192.168.0.3.

If yours are completely different groups of numbers, that's your problem. You need to do ethernet troubleshooting. Please refer to this:

Why can't I get Ethernet to work?