Steps:

1. Browse C:\WINDOWS\system32\drivers\etc
2. Find the file named “HOSTS“
3. Open it in notepad
4. Under “127.0.0.1 localhost” Add 127.0.0.2 www.sitenameyouwantblocked.com , and that site will no longer be accessible..

(127.0.0.1 localhost 127.0.0.2 www.blockedsite.com –>www.blockedsite.com is now unaccessable<– For every site after that you want to add, just add “1″ to the last number in the internal ip (127.0.0.2) and then the add like before. IE: 127.0.0.3 www.blablabla.com 127.0.0.4 www.blablabla.com 127.0.0.5 www.blablabla.com)