How to permantly block a site on your PC ?

It's possible to block a Website using this manual and simple trick.Whenever User types any domain name in the address bar,the browser actually sends a request to the DNS servers for the Respective Ip Address of that website.So,Every browser before sending requests to DNS server checks the hosts file present in the c:\windows\system32\drivers\etc\   for IP Address of the domain name entered in the address bar.So adding invalid IP Addresses entries to the hosts file will result in the Ridirection of browser to an Invalid site.User Will experience below error message.

Steps :-

- Start->open Command Prompt-> Type 'start C:\windows\system32\drivers\etc\' and press Enter.
{My operating system is installed on C: Drive}

-Open HOSTS file with notepad.Add invalid Ip Addresses followed by the website name user wants to  Block and save the file.

-In Case the user wants unblock the website.Just Erase the changes done to the HOSTS file and hit save.