Open a Command Prompt and run a Ping command to the website that won't respond. Make a note of the IP address displayed in the output from the Ping command.
What is the IP address shown in the Ping command?
Does the result from the Ping command show 0% lost, 100%lost, or something in between?
Open Notepad, click File > Open
Type (or copy >paste) the following into the "File name" box of Notepad's "Open" dialog and then click "Open"
C:\Windows\system32\drivers\etc\hosts
The following lines are the default contents of the hosts file (note that there is no file extension). Any line in your hosts file that DOES NOT start with a # character will act to redirect an IP address. Thus, if the IP address of the website you're
trying to reach (shown in the Ping command) is mapped to localhost (see example in the default contents), you'll see the behavior you describe.
You can only look at the contents of the hosts file by following the directions above. If you want to edit the file and save the contents, see
https://helpdeskgeek.com/windows-7/windows-7-hosts-file/
DEFAULT HOSTS FILE CONTENTS BELOW
Copyright (c) 1993-2009 Microsoft Corp.
This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
This file contains the mappings of IP addresses to host names. Each
entry should be kept on an individual line. The IP address should
be placed in the first column followed by the corresponding host name.
The IP address and the host name should be separated by at least one
space.
lines or following the machine name denoted by a '#' symbol.
For example:
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host
localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost