Instructions to do:
1) Go to this directory [c:\windows\system32\drivers\etc], directory may change according to drive used for os installation.
2) then hit enter
3) find a file named "hosts"
4) Right click on it and open with word pad.
5) In the last link of the document type the IP* address of yahoo space www.Google.com (Vice versa for other sites)
6) now save it
7) restart the browser if its already running
8) Now try it, It works perfect
IP*: to find IP address of that website Goto start ->Run > type cmd > enter. Now you have a new window on desktop. On that type this without cotes "ping www.yahoo.com"
replace yahoo.com with your preferred site and then enter it ,Repeat the first four steps and remove the last line that you have inserted and save it and restart browser. Now its back to normal
try this on your frieds pc and public pc and make them blink.