Domain unreachable

Hi,
I m trying to connect one of my computer, which has windows xp as a operting system,to my domain but it can not able to connect with my domain(kumar.com).It shows an error.
An error occured when DNS was queried for the service location (SRV) resource record used to locate a domain controller for domain kumar.
The error was “A socket operation was attempted to
an unreachable host”.(error code 0x00002751 WSAEHOSTUNREACH )
Plz let me know abt the error and how do i can solve it?
thx
Raj