norton internet security 2012 wont update

does anybody know what is wrong with norton internet security 2012 as to why it will not update  i keep getting the message that my antivirus and malware protection is out of date , i ran the eraser and did a couple of scans  and even replaced the system battery but it still wont work  i have over 70 days left on my subscription   i am running vista operating system 64 bit    i tried to find some solutions on this fourm but none of them seem to work