I have TWC for cable internet and use one of their Motorola/Arris combination modem/router devices. Thus, it's 2 devices in 1. Today, I purchased the Netgear Nighthawk router hoping that might help with a dead spot I have in my house. However, I'm wondering if the Nighthawk router will conflict with the built-in router functionality in the Arris device? In other words, can I still use the Arris for it's modem function but use the Nighthawk router in place of the built-in router in the Arris?

I can't find much online and I'm not confident in what the TWC chat rep told me. She said it would be fine but I had to explain above about 3 times before she understood what I wanted to do.

You'll need to turn off the router function in ur TWC router - make it just a modem. Or, put the new router into bridge mode - ur new router should have instructions on how to do this easily.