Browsers are not workin...????

Hello,
heyyy.......... actually i want to know...if yourr net is working properlyy.... everything is working properly like messengerss,, u torrentss.......etc except browserss i meann when i write an address in an adress barr......... then itz not showw any type off reaction...just gave msg it will not be connected........ i want to know how to slove my this problem...... please do tell me how to remove thiss........ my window is vista.... so plzz do tell me as soon as possible if u know how to solve this problem... thanxzz