I have successfully installed DNS and DHCP to service my Windows XP clients.

The clients will resolve the fully qualified name, but not the hostname on
it's own. I am assuming this is because the clients are not configured with
the fully qualified name.

I believe this can happen via DHCP, and I have looked at the NIS Domain but
this has no positive change towards resolving this problem. I am wondering
of someone can assist me with this issue.

Just to explain in another way, assuming my internal network was
network.com. And a host on the network might be called client1. My clients
cannot resolve client1, but can resolve client1.network.com. The servers
resolve this fine so there is no problem with the servers.