Jack has an issue with his iMac getting knocked off the network using Wi-Fi. He has to reboot from time to time. Leo says that Apple has issues with Wi-Fi and it's a black art. Leo thinks it may be an issue with the cable modem. Jack should ask his cable provider if he can buy his own, and pick up an Arris DOCSIS 3 modem. Even though they gave him one, he's just renting it and it's likely a used one. He should buy his own, along with a router, and he'll get better results and save money on rental fees as well. Leo recommends getting an Apple Airport Extreme.