RDR error on PDC

In our campus students have pcs in thier rooms and often they create thier own workgroup and few have installed server. Rooms are on diffrent vlan than lecture buildings. But I see lots and lots rdr error on my pdc stating :
“The master browser hasreceived a server announcement from the computer MUGUET,the master browser is stopping or an election is being forced”.

What can I do to stop these errors.