synchronization

I have a BDC that will not recognize, net permissions of specific accounts. When I try to sync this with the PDC, it comes up with a window trying to start netlogon service, followed by can’t start service PDC already exists on this Domain?? I alsocan’t see the BDC and its users from the network neigborhood window. Yet I can still acquire apps from that BDC. Can anyone tell me whats going on. If you need more info e-mail me. Thanks