Error 783 - Can't enable ICS
Symptom: When you try to enable ICS, you may receive the following error message: "Error 783: Internet Connection Sharing cannot be enabled. The LAN connection selected as the private network is either not present, or is disconnected from the network. Please ensure that the LAN adapter is connected before enabling Internet Connection Sharing."
Resolution: When enabling ICS, your computer is assigned the 192.168.0.1 IP address, and if this address is already in use on the network, you will get this error message. To fix this problem, disconnect the computer using the 192.168.0.1 IP address from the network, or change its TCP/IP settings to use DHCP.