Windows Server Networking

I have two PCs networked and the icons show both are connected to the Internet but the main PC cannot find the host in order to send an email but the other PC can and does send the email How can this happen? ...

Hi there, I have an AD controller with DNS integrated zone and also running Wins for compatibility with older clients and domains. In the Wins server setting, the IP should it point only to the server itself or also to the secondary servers located on other computers? ...