Steps to block an unblock internet sites:
Go to Start and type RUN .
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 (see the pic below for example
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.
Some time in windows 7 pc u just need to give administrative permission to edit on hosts file but this trick works well without any software you can block any website on your pc.
Enjoy stay tuned for all daily Updates.:)