virtualbox.org

OK, So...I am the IT Director here @ work and what I am trying or more like attempting to do is: I have 1 physical PC running Virtualbox (Server 2008 r2 Enterprise w/ AD) Now comes the fun part. I have 5 PC's on the network which are running their own virtualboxes ( Windows 8.1 Enterprise )What I want to accomplish is have those 5 pc's connect to the domain(which is the Virtualbox running Server 2008 r2 Enterprise) I want to be able to get online with all 5 PC's, Share files, printers, and map drives from the server by using GPO to map drives for the 5 users. Is this at all possible?

A VM is just an ordinary PC, except that it runs on simulated hardware. It can, within reason, do anything that any other PC could do. It can especially do anything on a network which any other PC can do, though you have to pay attention to the networking mode: bridged if the VM needs to work like a server, NAT otherwise.

It is not impossible and is certainly plausible. If you use bridged networking, all of the machines (virtual and physical) will appear to be in the same network. From a networking point of view, your situation would be similar to a network where some machines run in a workgroup and some in a domain.

As far as VirtualBox is concerned, all you need to do is set all of the vms to use bridged networking. There are quite a few things you will need to do, but none of them are in any way related to VirtualBox. They are the same as you would need to do in the physical setup described above.

We have that kind of arrangement running now in our office. A Windows 7 Professional host, SBS2003 as domain controller in a guest (yes we do have to upgrade), with an XP and three other Windows 7 guests. XP is a workgroup member, Windows 7's are domain clients.
Several other physical Windows 7 PCs in the office and shop floor are domain clients, and the two Windows 7 and one XP guests running on my Windows 7 Professional host are domain clients too. My host is in the workgroup.
All these hosts and guests can access each other completely. Bridged is my Virtualbox network flavor.

(BTW, don't put your PC that is hosting your domain controller on the domain, leave it in the workgroup. Problems will arise when one day you can't log into the host PC because something in the trust relationship has gone wrong and you have to re-attach the host to the domain, but the domain controller can't be reached because it isn't running yet, but you can't start the domain controller because you have to log into the host to start it, but you can't log into the host..... There's a hole in the bucket, dear Liza...)