trust relationship between a workstation and a server

The trust relationship between the workstation and Primary could not be
found, and I was to re-establish the trust between the primary and the
workstation.

I have this problem with EVERY Windows XP Pro workstation on my network.
Every Windows 2000 Pro workstation works fine. My domain controller is
Windows 2000 Advanced Server.

I did try Usermanger for domains / policies / trust relationships, but I
could only add domains, and not computers. I did try typing the computer
name, but it said the domain controller for this domain could not be found.

If anyone could help with information, then I would be most grateful.