If your phone box looks similar to what's in the first link; and you have a bunch of thin red/green or blue/white type wire in there (One pair probably to each jack, or you only have one or two pairs and they are daisy chained in the house), and MOST IMPORTANTLY, you have a small phone cord in that box,,,,, then JUST UNPLUG THE PHONE CORD IN THE BOX. Then, you're done. That is specifically designed, to disconnect YOUR JACKS from the phone company's line, so if your phone system didn't work, you could unplug that jack, which disconnects from all your house jacks, and plug a phone into it.

So, if you unplug that jack and LEAVE IT UNPLUGGED, then all your jacks are disconnected from Ma'Bell. Simply take the phone jack on the voip adapter and plug it into a phone jack in your house. Now, ALL your jacks will work.

If your phone box doesn't sort of look like that, and there's no jack cord in it to UNPLUG, then take a pickture of it and post it. Then we can tell you. Best of luck. Mike....