We have a SBS2003 server that does dns but a second server 2003 standard that is the dhcp server. Most pc's are fine, they connect fine every morning, some times if the pc is moved from one desk to another it will not log in any more. It claims the domain controller cannot be found.
I had this issue before and was asked to remove the computer from the list on the server under active directory users and computers, this worked a while a go but makes no difference now.
If i unplug the network cable, it lets me log in to the pc, i can then plug in the cable and the pc is assigned a network address and the user can access the server and the internet as normal.
If I assign a static ip address to the pc everything works well.
I think it has something to do with DHCP but not sure what.