Thanks guys... Thanks for helping me out of this.... You're suggestions worked a lot in troubleshooting the problems.... I thought at the prior stage of faulty Ethernet controller but I proved wrong it got sorted out by installing drivers, before that I tried installing drivers from multiple sources but all proved wrong so ... I started thinking of a chance of faulty Ethernet controller... But things sorted out with the help of
@bssunilreddy also ... After installing my pc couldn't boot up .... I don't what was the reason Again..I had to reinstall the os... After deleting the previous partition again after repeating the whole procedure... Now it's working fine so thanks guys... This forum is a great way to get things sorted out.... Thanks for you're help!!!!