Unable to connect to client from server

I am unable to connect to a client from the server, The client is able to log onto the network with no issues, Client is XP Pro Sp2 and Server is Win 2003

If i type \\xxxxxx\c$ i get the message returned stating the network was unable to connect to the address.

Security is locked down via group policy, yet having not set this network i am reluctant to dig in group policya and cause more issues.