Modem and Router issues.

Thanks for taking a look.  I am not renting my modem from Comcast/xfinity.

I got my own modem, then an external wireless router.

Here is where I run into a severe problem.

I am 59 years old.

 I think, and speak, in complete sentences and entire paragraphs.

I try to use grammar correctly.

I don't use cell phone text haiku.

I don't type with my thumbs.

I don't say "like" and "you know" every fourth word when speaking.

I have an attention span longer than ten seconds.

As a result,  when I try to describe my computer problems, everyone complains that it is "too long to read".

Well, if you're that busy, what are you even doing here on this forum?

This is long. Get over it.  The reason it is long is, it will take less time for you to absorb all the facts

here than it would be for us to go back and forth with dozens of questions and answers for three days.

Yes, I've already tried getting help from the manufacturers of the modem and the router, and no, they have not, and likely will not, reply, since these are not under warranty.  And yes, I have tried Search Engine and Tech Forum solutions.  Nothing is working, and some of the advise is so abstruse it's useless to me. 

Windows 10 Home, version 19042.1288

Amazon page where I bought computer says:

CyberpowerPC Gamer Xtreme VR Gaming PC, Intel Core i5-9400F 2.9GHz, NVIDIA GeForce GTX 1660 6GB, 8GB DDR4, 240GB SSD, 1TB HDD, WiFi Ready & Win 10 Home (GXiVR8060A8, Black)

Amazon page where I bought the modem says:

ARRIS SURFboard SBG10 DOCSIS 3.0 Cable Modem & AC1600 Dual Band Wi-Fi Router, Approved for Cox, Spectrum, Xfinity & others (black)

Wireless router is Netgear model R6400v2, no memory of where or when purchased.

Absolutely no access to another computer

Absolutely no access to any functioning cell phone

when originally purchased, I believed the computer had a wifi router built in. 

It certainly has antennas sticking out of the back of it. 

  However, even after literally days of struggling with tech support, I never got that to work. 

It is very important for you to understand that this aspect has NOTHING to do with the current external router, which has worked in the past. 

Getting Errors "Wifi does not have vailid  IP configuration" and "Ethernet does not have valid configuration"

The official Windows forum showed a "solution" that called for many steps, one of which led to having to go into Windows Settings and click the Network Reset Button......that button does not exist on my computer, as screen shot number 13 shows.

Conditions that led to this situation:

1. I have never wanted or needed wireless internet, just used a coax cable connected to a modem;

2. A pro-wireless friend gave me a gift of an Echo Dot, which wouldn't work unless I had a wireless router.  At great expense and reluctance, got a Netgear model R6400v2.

3. Alexa did work, but not reliably or in ways I wanted it to. Alexa pretty much reluctant to obey, and very eager to sell me things.  Not what I want in my home.

Adittionally, internet speed of the Netgear was disgusting, something like 13MBPS, when the modem was 115MBPS.   . Deep anger at lost time and money. Disconnected the Echo and the Netgear.

4. Many weeks later, cell phone stopped working, could not make outgoing calls, and tech support insisted to get it functioning again, I had to have a wireless connection.
 Reinstalled Netgear, but cannot get phone to connect to it. Tried using hotspots in four areas outside my home, can't launch phone. Gave up.

5. Came home, have installed Netgear exactly as before, installed Echo device exactly as before.  I was surprised to discover that I could make outgoing calls using only the Echo, without the phone, no idea at all how that works.

6.  Unwilling to live with the sickening slow Netgear internet speed, took it off, took Echo off.

7. weeks later, needing very badly to make an outgoing call, connected echo and netgear again, exactly as before.....and suddenly the Netgear won't connect me to the internet.  Cables, connections are all identical to as before. Router is less than two feet from the computer.

8. This launched the process you see shown in the screen shots, trying to solve this, steps I have already taken. As of this posting I have rebooted computer, modem, echo and router at least 25 times.  The shots are numbered as best I could in the order I took the steps.  The screen shots can be seen on the site Bleeping Computer under the title "Cannot Put Up My Topic"

Update:

Hooked up to the internet exclusively with modem only, no router:

Went back to the Netgear manual, shown here:

https://www.downloads.netgear.com/files/GDC/R6400v2/R6400v2_UM_EN.pdf

Note on page 13 it shows a very specific illustration showing correct cable hookup. That configuration has worked fine in the past, no longer working.

Next, I go to the Troubleshooting section of the manual, which leads to the Netgear website.

On this page, I click on Guided Assistance:    https://kb.netgear.com/27199/I-can-t-access-my-router-what-do-I-do

This is a series of yes/no questions.  The first question is "Are you able to access the internet or other websites?"

Now, maybe it will be helpful to explain my way of thinking. To me, this question only confuses and enrages me.  First of all, how could I be reading a web page if I did NOT have access to the internet, since that is where this question appears, on the internet.  Next, did the question REALLY mean, will the ROUTER access the internet, and if so, why didn't they phrase it that way. 

So right there, with question number one, I am stuck. Is there something inherently wrong with me, or is this "help" thing totally broken?

I choose "no".

This produces: