Networking virtual machines - issue

Hello everyone. I'm not totally certain this topic should go in this thread so if it should be elsewhere, mod's, of course feel free to move it. Thanks.

Okay, I have a basic network setup at home. I have a Netopia wireless DSL router and connected to that I have a small network switch. In this room I have 6 personal PC's connected, all wired directly into either the Netopia or the switch. All of the PC's are running Windows XP Professional except for one, which is running Windows Server 2008.

On 2 of the personal PC's I have Microsoft Virtual PC installed and have a Windows Server 2008 virtual machine on each of them. So that makes a total of 3 instances of Windows Server 2008 on my network - one installed directly on a PC and the other two being virtual machines. They each have hard coded IP address information and can ping the gateway (the Netopia) and devices on the Internet (I can ping yahoo.com, for instance).

Here's some background on why I'm asking for help. My problem arises when I try to go through some exercises where I'm trying to get these 3 2008 servers to communicate with each other. The firewall's on them are off (I did this as a step to resolve the issue but it didn't make a difference) and they cannot ping one another. I tried to go through some Active Directory Domain Services and DNS exercises but couldn't get through half of them because the servers aren't communicating, or aren't able to communicate over the network.

The exercise where I get stuck is trying to have me create a manual zone delegation. The exercise wants me to create a new zone in the forward lookup zones, which I'm able to accomplish. When I get to the part where it wants me to create a new delegation, that's where I get stuck. I put in the static IP address and it doesn't work. I get some error message (I can't remember what it says specifically) but I know it has to do with the servers not being able to communicate.

Any help you can give me would be great.