Block any website without any third party software

Any website can be blocked without using any your party software.

1)   For Windows 7
       Navigate to C:\Windows\system32\drivers\etc\hosts

       On Windows NT it is:
       C:\WinNT\system32\drivers\etc\hosts

      For Unix/ Linux
      /etc/hosts

2)    Open the file "hosts" in Notepad. It has no extension.

3)    Type in 127.0.0.1 <space or tab> and then www.domain_name.domain extension.

4)     Save the file and exit.

This will block Facebook.com on the system.