@aliciaha 

Try different browsers and even a diffrent password.

Have tried in Firefox and Chrome.

Have tried different passwords, different lengths, w/ and w/out special characters.

@aliciaha 

Two other things would be to factory default the router by holding the reste for 10 seconds. Log in, and try to change it. If that still fails. Download the latest firwmare here:

https://static.tp-link.com/2019/201904/20190415/Archer%20A7(US)_V5_190403.zip

Even if you already have the latest firmware, download it, extract it, and upload the bin file to the router. 

Here is how you update it: https://www.tp-link.com/us/support/faq/2139/

Resetting with a paper clip on the router means my Admin log in name goes back to the default as well, right?

@aliciaha 

You can only change the password, not the username when in the menu you referenced.

Were you using an email for your login name?

No, I mean if I physically reset the router, when I go to log onto the tplinkwifi.net page, the Admin password  log in will be back to the default log in.

Am not using an email address as a password, lol.

OR are you saying that if I'm logged into the tplinkwifi.net page while the router is reset, I *don't* have to log in again.

@aliciaha 

After you do the reset on the router the user name and password will both be "admin" (without the quotes).

Welp, pressed thereset button for ten seconds. Didn't reset anything as I had to use my log in name (not "admin") to get into tplinkwifi.net.

At this point, I give up. I will keep the original password. I need to set up my tp-link Nano router that I use as a range extender at home.

(What a nightmare that is to set up during travel, btw. I had to reset it so many times that I ended up just keeping the admin/admin log in.)

@aliciaha 

As you are holding the reset button all the LED lights will blink on then turn off. It seems like the reset did not go through properly. Try to hold the reset until you notice that from the LED Lights.