Cannot connect to WiFi - Dell Studio 1555, Dell Wireless 1397, Win 10, Troubleshooting Steps

Hey, help please. I own Della Studio 1555 and as a Dell Wireless 1397 network card. Once upon a time I did not want to connect to WiFi at home and the problem persists until now. I didn't do anything the day before, I didn't install any software, Win 10 didn't download any update.
The phone connects to WiFi without any problem. When I turn on the hotspot on my phone - the computer connects without any problems. Nobody tampered with the router.

Searching for a solution on the network, I took the following steps:
- I uninstalled and reinstalled the network card, i.e. I entered Device Manager -> Network adapters -> I chose Dell Wireless -> Uninstall and then Action -> Scan for hardware changes
- I typed on the command line (started as admin), because somewhere on the network I found this solution:

Quote:

ipconfig / release
ipconfig / renew
ipconfig / flushdns
ipconfig / registerdns
arp -d
nbtstat -r
nbtstat -yy
netsh winsock reset

- I was checking if the card has settings, that when the laptop is on a cable, some battery saving turns on, but none of these things

I have no idea what to do anymore ...

Use inssider 2.x, perform wifi scan, show results.
WIFI network name?

5e4fd9 network



I will add that I noticed, having opened the Network connections folder, that when I want to connect with this WiFi, the card turns off for a moment, i.e. it changes from black to white icon. I don't know if it's important.

Crowded there on the 2.4Ghz band.

If you move the laptop near the router, does it change anything?

WIFI router model?

Added after 8 [minutes]:

What high speed internet connection do you have?

Well crowded, but for two years there were no problems. When you change the distance, nothing changes. I go to the router and do the same.
CISCO EPC3928S router.
I connect about 5mbps with what I associate, but I don't remember well.

Start the computer in safe mode + network support, does it change anything?

He's been trying for a long time to connect ... He connects and nothing. Neither message nor connection. : /

Delete / forget WIFI connection and reconnect.

I have done it a long time ago The network is not saved.

Download and run linux live (eg Linux Live Mint) on USB and check if linux live connects WIFI.

Ps what I noticed is that no device wants to connect to the 2.4GHz network and 5GHz work all correctly, but my paw has the unfortunate 7260N card and I can't change it. Reset the router and everything works, the win10 scan showed the message that you cannot connect to the hidden network, is it possible that the router is hiding 2.4GHz by itself?
For both it was the same password, I changed it to another maybe it will help something.
I need someone who could help in the removal of the whitelist