I'm not certain that Time Warner does this, but lots of cable providers authenticate their users by checking the MAC address of the network card that's connected to the modem. If your father set up his system with the iMac originally, then switched to the ABS, the modem sees a different network card (the ABS, like all ethernet devices, has a MAC address), so it refuses to connect.
Your father has two courses of action available, and which one he takes depends on what his terms of service are. If Time Warner only allows a single computer to be connected to the modem, then he should probably invest in a gateway router that will "clone" his iMac's MAC address. They're available at a lot of outlets, such as BestBuy, Office Depot and OfficeMax, and can be had for less than $50. I offer this as the first option because many, if not most cable operators refuse to support more than one computer connected to the modem.
The second course of action, if his terms of service allow it, is to call his tech suppport number and tell them that he's changed network cards. He may have to read off the number on the bottom of the ABS (it's six hexidecimal numbers in the form xx-xx-xx-xx-xx), or they may simply tell him to unplug the ethernet cable from the modem, wait ten minutes and plug it back in. However, I doubt that the Great Satan of All Media is going to play nice with your Dad, so make sure you both read those terms of service before you procede.
Your father has two courses of action available, and which one he takes depends on what his terms of service are. If Time Warner only allows a single computer to be connected to the modem, then he should probably invest in a gateway router that will "clone" his iMac's MAC address. They're available at a lot of outlets, such as BestBuy, Office Depot and OfficeMax, and can be had for less than $50. I offer this as the first option because many, if not most cable operators refuse to support more than one computer connected to the modem.
The second course of action, if his terms of service allow it, is to call his tech suppport number and tell them that he's changed network cards. He may have to read off the number on the bottom of the ABS (it's six hexidecimal numbers in the form xx-xx-xx-xx-xx), or they may simply tell him to unplug the ethernet cable from the modem, wait ten minutes and plug it back in. However, I doubt that the Great Satan of All Media is going to play nice with your Dad, so make sure you both read those terms of service before you procede.