by neil » Apr 13 05 9:31 am
This depends on how the client machines are connecting through WinGate. If via NAT then in the ENS properties, under the Port Secuirty tab, Add an action that will block the MSN and Yahoo messenger ports (sorry i cant remember what they are off the top of my head - if you look in GateKeepers activity pane while some one is connected to those services, you will see the ports listed there), making sure you tick 'Local Computers to the internet'. You may also want to block 'Local computers to the WinGate PC'.
This latter method should also block them from connecting through proxies in WinGate.
Regards
Neil