Windows XP doesn't join to domain

[weiglas]

Hi,
There is a Windows Server 2008 on my work and all PC's are connected to the domain.
Also there was a Windows XP guest in this Windows Server for some especific host files, and was connected to the domain too. But the VHD turned unavailable, so I created a new VM from the VHD from backup, and this VM doesn't allow to login in any account showing the message that the domain is unavailable.
I changed the network setting like was in the old VM, but didn't work.
I tried to change the password of the local Administrator of the VM (once I didn't know, because all this thing was created by a person who doesn't work here anymore) with a LinuxLive boot, but it seems that not changed anything.
What I'm looking for in this forum is how to login to the domain, because I also tried to copy the files with LinuxLive, but the system that hosts the files is a open source project management tool (dotProject), and I installed this framework on my PC and copied the files to my installation folder, but I dont have the enough knowledge in MySQL or whatever this framework uses, and the files doesn't showup in the.
So, if guys you understood all this what I writed and can help me, thanks! haha

[BillG]

The account or password does not matter. You can enter a domain username and password later (if the machine can find the DC).

It probably has very little to do with VirtualBox. The important thing is that the PC can find the DC. Is it in the same network and the same IP subnet? Does it use the DC's IP address as its only DNS server? Can it resolve the domain name? (check by doing nslookup of the domain name from a command prompt).