Problems with DNS.

Hi,

I seem to have problems with my principal DNS, and it cause problems with my users. Each time a user that are on windows XP try to login it takes forever if don’t had the DNS manually. But the principal DNS can’t go to internet, due to the fact that i can’t see the root. Anyways, my question is do i have to reinstall the DNS wich means reinstall the wholes active Directory, or is there a way that i can save my active directory but with solving thoses problems.

On the client machine, the GPO are not apply. In the event viewer i receive the error userenv. If anybody can help me, it will be appreciated.