You would like to optimize your IIS server. You discover from Performance Monitor that % Processor Time is low but the % Network Utilization is high. This indicate that the network needs to be optimize. You can redesign the network to support higher bandwidth - cables, routers, switches, WAN links, etc and if the network card is also a bottleneck then you can upgrade it to a higher speed/quality. Another option will be to add a second network card to the server.