The Hosts file is a file within Windows which can be used to map IP addresses to hostnames, and can also be used to override settings from DNS servers. The file can be found at C:\Windows\System32\drivers\etc however you will need to run NotePad (or Notepad++) as administrator, as it is a protected system file.
Search for Notepad, then right-click and “Run as Administrator”.
You can then add and edit the hosts file as nessecary. The lines starting with # are comments and will be ignored by the system.