Always been gravely disappointed with Windows Networking in general. When I lose my Internet connection on my LAN, I'd like to just plug my iPhone into my PC and share the connection with any PC on the LAN. I have no problem using my iPhone as a modem on the PC it is connected to. Wouldn't it be nice, and make sense that Windows would see the Internet connection go out and automatically re-route everyone through my iPhone until seeing it back up then automatically re-route. But I guess that may be asking too much, as we've only put men on the moon up to this point. I've shared the Apple Mobile Connection. The Internet Connection Device shows up on the network. But I'm guessing every PC is still trying to route through the router's Internet connection, and not the ICS connection. If it involves something like temporarily setting static IPs or temporarily disabling the DNS server on the router and refreshing all the connections, forget it. It should be all automatic in my opinion.

Hi, Internet Connection Sharing (ICS) is a method to share one Internet connection among several computers instead of a router. Please don't use ICS on a network with domain controllers, DNS servers, gateways, or DHCP servers. And don't use ICS on systems configured for static IP addresses. If you have a router, it is not recommend to enable ICS to cause confusion. Niki Han TechNet Community Support

Hi, Internet Connection Sharing (ICS) is a method to share one Internet connection among several computers instead of a router. Please don't use ICS on a network with domain controllers, DNS servers, gateways, or DHCP servers. And don't use ICS on systems configured for static IP addresses. If you have a router, it is not recommend to enable ICS to cause confusion. Niki Han TechNet Community Support