Cant see other computers on the network, but can see from the erver

Hi all,  This is such a headach, I'm not yet an expert but have tons of issues lately.

We had problems with the server, I noticeed that on every system (25)  I cannot browes to see nany systems on the network. it sayd something like. domain is not accessable, you may not have permissions, at the end it says the SERVER NOT CONFIGURED FOR TRANSACTIONS.  please  help!

I changed nothing, I know the serve did restrat on it own a few times yerday, did a virus scan fond and cured 6 ussues.  today it up and people are able to access programs, but cannot see the network to map drive etc.  

I cannot even use remote desktop connect to see the server from another system on t he LAN anymore.  any ideas is much appreciated