The proxy server is not responding.

Thank you for handling this issue, and I just realized that the Apply button is inaccessible.
Indeed,
I have already done several times what you indicate in "Internet Options/Connections/Network settings/"
I checked "Automatically detect settings" > Ok and > OK

BUT in response to your question: Did you click "Apply" then "OK" after your modifications? I just noticed that I could only click OK because the Apply button is grayed out and inaccessible.

This may be the reason for losing changes once the computer is turned off.
See you soon.

Are you logged in as an administrator or guest account?
If guest:
Try using the administrator account
If administrator:
Try running Internet Explorer and modifying (just to modify)

--
"I am one of the most powerful sorcerers in living memory."

Thank you The Deceiver,
I am on the Administrator account.
When I change the homepage in Internet options, for example, I have the apply button

BUT

In Internet options, under Network Settings, for changes, I do not have the Apply button after making a change.
See you!

I just noticed that "Apply" is not available sometimes either
So that's not where it comes from.

What is the name of the proxy?

--
"I am one of the most powerful sorcerers in living memory."

What is the name of the proxy?

How to find this information?

It's not a big deal

Do you have Mozilla Firefox?
If yes:
Is there the same problem?

--
"I am one of the most powerful sorcerers in living memory."

I had Mozilla Firefox, but since the problem was the same with Firefox, I uninstalled it before asking for help on CCM.
It's worth mentioning that the same problem exists with Maxthon.
Looking forward to hearing from you.
Best regards.

Try reinstalling Firefox and see if the problem persists on Mozilla.

“I am one of the most powerful sorcerers in living memory.”

Good evening,
I had the same problem (maybe not the same port 8877). It's probably due to a virus.
I fixed it by running antivirus, probably Microsoft Security Essentials and/or by updating the web browsers.

Good evening nicososinfo,
Thank you for the suggestion regarding a virus.
I had also thought of a virus, but Karpersky 2013 did not detect anything during a full scan a few hours before I posted my help request on CCM.
Malwarebytes also found nothing during a full scan after Karpesky 2013.
It’s worth noting that the computer takes a long time to respond at startup after being turned off, which I attributed to Karpesky.
The version of Internet Explorer is 10.
Thank you both for your help.
See you!

I installed Firefox and, after a reboot, I no longer had any proxy connection errors in both Firefox, IE, and Maxthon.
Since then, things have deteriorated, and IE & Maxthon can no longer find the proxy, and the network settings have reverted to what they were before.
However, Firefox is operational.
What should I do now?
Thank you for your response.

IE and Maxthon still don't work?

--
"Je suis l'un des sorciers les plus puissants de la mémoire vivante."

IE and Maxthon still don't work. Only Firefox can access the internet.
I've shut down and restarted the computer 3 times, it's still the same.

Reinstall Maxthon (maybe it will work)
Install the latest version of IE

Also try setting the port "80" (HTTP) instead of 8877

"I am one of the most powerful sorcerers in living memory."

To reinstall Maxthon, I only had internet access through Firefox, but for the installation of Maxthon which connects to the internet, I had to redo: Internet Tools / Options / Connections / Network Settings / removal of the checkmark in the proxy server and ok.
No improvement for Maxthon after reinstallation; nor with IE.
No positive result with 80 instead of 8877 in HTTP.

The port 80 is still there?
I thought it would switch back to 8877
You put port "80" in the field next to the address

port 80 = port usually used by HTTP
--
"I am one of the most powerful sorcerers in living memory."

I detail what exists when the internet is not working due to "The proxy server is not responding"
Internet Options / Network settings /
Checked option for:
1) Automatically detect connection settings
2) Use a proxy server for your local network with
2.1) Address blank
2.2) Port blank
Then, by clicking on Advanced I get
HTTP: 127.0.0.1 Port: 8877
Secure: 127.0.0.1 Port: 8877
Exceptions: *.local

To access the internet, I need to uncheck:
Use a proxy server for your local network

I hope this helps you (note that at the beginning of our research, port 80 was present in:
Use a proxy server for your local network with
2.1) Address blank
2.2) Port 80

Hello !

Check "Use a proxy server for your local network"
In "Advanced"
In HTTP set "127.0.0.1", port = 80
Remove all others
In exceptions
Remove "*.local"

--
"I am one of the most powerful sorcerers in living memory."

Hello and Happy Sunday,

The result is the same (proxy blocking) with the box "Use a proxy server for your local network" checked and
In "Advanced"
In HTTP "127.0.0.1", port = 80
All others erased
with In exceptions "*.local" erased

However, when I turned on my computer this morning, I had network connectivity with IE, Maxthon & Firefox and in Internet Options / Network settings /
Use a proxy server for your local network was not checked.
BUT
A few minutes later, the connection became impossible and in Internet Options / Network settings /
Use a proxy server for your local network was checked.
A program or virus must be loading and blocking my connection to the proxy by checking in Internet Options / Network settings /
Use a proxy server for your local network
Looking forward to your reply.
Best regards.