|I dont think you need worry about resetting the MODEM. If all you have in Ethernet cable coming into your house it means the MODEM is in the exchange and it is the MAC address of the MODEM that the ISP sees.|
First try plugging the Ethernet cable directly into the NIC on your computer and see if that works. Reboot the computer and go to command prompt and type ipconfig /all.
If you have IP addresses and a gateway address then it should be working. If not you need to contact whoever has control of the MODEM and get them to do something.
Once that is done you can plug the cable into the router and another cable from the router to computer and then set about configuring the router. Cloning MAC addresses shouldn't be necesarry.