Why does the computer have a double name?

Question

Windows

Put the program with the server part on the computer. When launched, it makes a request in which the computer name appears, but it does not match the current name, judging by the error text. I changed the computer name to the name from the error, the program requested the old name. How can I fix this?
Here is the original error:

And this is what I got when I changed the computer name to the name from the error:

Answer 1

The problem turned out to be an unclean installation (there was already ParaGraph on the computer and it was not completely cleaned). Vanilla installation on another computer was successful.

Answer 2

Full path to the hosts file: %WINDIR%\System32\drivers\etc\hosts
Write down the IP address of this computer and its name in the form: 127.0.0.1 MASHA-PC
127.0.0.1 replace with the IP address of your computer, of course.