Can’t connect XP Pro to Windows 2000 domain.

I’m just a beginner when it comes to networking and I hope someone can help me.
All of our computers here are joined to a domain and no problems. I purchased a new Quad-core desktop HP Slimeline (s5280t) and tried to join the domain using XP PRO and the error was The error was: “DNS name does not exist.”
(error code 0x0000232B RCODE_NAME_ERROR).” I have no problems connecting our Old computers to the domain, but the new Quad-core can’t connect. I was wondering if there is a problem because the processor is Quad-core? I already added a Computer and User Name. Please help… Thank you.