Registration of DNS record failed

I have installed Winproxy on my W2K server for internet access to my clients

In my server Primary and Secondary DNS entries
are 203.196.x.x and 203.196.x.x( as given by ISP)

My problem is that, getting a lot of errors in event log saying Registration of DNS record failed

i tried removing DNS entries , then from client machines i am not able to open some websites as it is not able to resolve
can any one help me to resolve this error- it is very urgent