Solution found! I took the laptop within range of another 'known' network that I WAS able to see and connect to - while connected, a friend helped me figure out how to run a driver update on the Intel(R) Dual Band Wireless-AC 3160 network adaptor. Then I brought the computer back home, crossed my fingers, said a prayer, and was finally able to see my new home network and connect!
Our internet provider (Spectrum) required us to install a new router & modum. I'm told the new equipment is dual band.  I can't find my network among the available wifi connections. I have a Dell Inspiron 15-5558 (2015 vintage, running Windows 8.1). We have several other phones, computers & tablets in the house, all are working fine with the new system. I tried the easiest thing - a restart - with no luck. After about an hour with Spectrum trying things having to do with their equipment, they said it's probably an issue with my computer, perhaps one of the following: 1) Drivers may not be up to date 2) Try new network card 3) Try 3rd party wifi card 4) Try a network adapter (goes in a USB port) I'm totally at a loss as to what any of this stuff is, which one would make the most sense to try first, or how to do any of it. I'd be so grateful for any coaching, but you'll probably have to 'dumb it down' for me...
Can't Find My Wireless Network