Many web-sites are locked in our college lab,can anyone tell me how to unlocked these locked sites?

Answer 1

one reason on blocking some sites in your comp. lab to prevent studs to access some sites that are not related to the study....
so.. ask the your administrator to unlock those sites. ..

Answer 2

if sites are locked more then likely the college's network is setup to prevent access and there is nothing u can do to change that

Answer 3

Complain to the administration. You probably have a system administrator who thinks he/she is God.