plz tell me main ny abi norton antivirus download kiya hy ar apny computer main install kiya laken ye option bar bar a rahe hy k ''15 days remaining buy now'' to plz mujy ap ye batain k ab 15 days bad ye expire ho jaye ga kiya ar phir mujy kiya karna hy ar is ka ye b batain k isy update kis tarha karty hen ?????