Master Browser

I have a new network and one computer has very slow access to the network. On the server 2k3 I get and event error 8003. The master browser has received a server announcement from the computer (the slow one) that believes that it is the master browser for the domain on transport netBT_tcpip_{c640ae99-aa90-4.

How can I clear the computer from being the master browser so that it can function on the network faster. I have tried a different cable to the switch and that still has no effect.