Network Path was not found

Dear All,
Our organaization is running under NT4.0 domain. Last week I installed a BDC for our domain, everything seems OK, but I have one problem which is: the server name appears in the Network Neighborhood when I dubble click on it I get the following message” \\tadbac is not accessible. the network path was not found”
Does anybody know how to solve this problem.

Regards,

Ammer