The Charter Internet installer installed new service last year and my wi-fi now has 2 networks I can connect to. One is mywifixxxxx-2G and the other is mywifixxxxx-5G the 5G network is CONSIDERABLY faster. My laptop and a gaming desktop I built a few years ago, only connect to the xxx-2G network, the 5G is not even available. I received a new laptop from work that connects to both. The 5G network is also a stronger signal.
I just built a new desktop that didn't have built-in wi-fi so I bought a TP-Link USB Wifi Adapter for PC N150 Wireless Network Adapter for Desktop - Nano Size Wifi Dongle Compatible with Windows 10/7/8/8.1/XP/ Mac OS 10.9-1. It only connects to the 2G network and the signal is very weak and slow.

Can someone explain what they installed and what Network Adapter specs do I need to connect to the xxxx-5G network?

I did ask him when he installed it, but he was actually kind of rude and told me there was nothing I could do to connect with my old laptop. (only 2 years old)