Follow this step: 
Enjoy :)
- Go to Start and type RUN .
 - Type C:\WINDOWS\system32\drivers\etc
 - Open the file "HOSTS" in a notepad
 - Under "127.0.0.1 localhost" . Add IP Name
IP - IP of the site to be blocked
Name - Name of the site 
Example :
127.0.0.1 localhost
210.210.19.82 www.sifymall.com
Sifymall is now unaccessable . For every site after that you want block , just add "1" to the last number in the internal ip (127.0.0.2) and then the add like before.
127.0.0.1 localhost
210.210.19.82 www.sifymall.com
Sifymall is now unaccessable . For every site after that you want block , just add "1" to the last number in the internal ip (127.0.0.2) and then the add like before.