Vista - could not see the virtual network adaptor in the Virtual machine

Hi,

I just purchase one HPDL380 box with Windows 2008 stnd (64bit). I set it up
as host server and create one virtual server with Windows 2003 R2 stnd
(64bit). The installation is successfully, I can see Host server and Virtual
server seperately. But these two servers could not communicte each other.
Only host server can access the office network system, which it uses virtual
network adaptor instead of physical network adaptor that works as virtual
switch. But there is no network connection in the Virtual server.

Actually I did the same setting in one test server which is white box (no
brand), and there is no any problem.

Does someone here help me to fix this issue?
Thanks in advance