Virtualbox make loose my DNS setting

[Rolmau]

Hi Guys,
I need serious help
I am ruining Windows 7 I installed Virtualbox Manager 4.2.2 to run (Windows Servers 2008 DC1, DC2 and XP)
DC1, DC2 & XP Network are set as "Internal Network, intnet" (my understanding is to make them in the same network from the same name "intnet").
I configure DC1 as AD DS + DNS server
DC2 can join the domain with no problem

But when I come back the next day to use my lovely new Network
I cannot join other OS in the domain even Windows XP the error giving is Active Directory Domain Service cannot be contacted

I log in with DC1 and DC2 with no problem but why I cannot add xp ? even
I also tried to join linux using likewise system cannot reach the DNS

Please help if you can

[BillG]

That probably has nothing at all to do with VirtualBox. That sounds like a simple Windows message.
Have you configured DHCP on your domain? If not, where is the XP machine getting its network config from? Is it in the same IP subnet as the DC? What is it using for a DNS address? It should be using DC1's IP address only.