You have Windows 98 now, so if your server is a domain server (Win NT, Win200 or any Samba) you can choose the option of giving access only to some specific users.
In the Network properties window look for the tab "Access control". There you have two option "Resources access...
Hi SahraniKasim. Do you need the Network connection only for getting info from server?? or does the server need info from the PC. If it is only incomming traffic you may stop sharing resources over the net, so nobody can connect to your critical mission PC.
About releasing free memory allocated...