Norton internet security doesn't work anymore!

hi!i’ve a windows vista home basic on a pc hp compaq 6830s , my problem is norton internet security doesn’t work anymore!i’ve used norton removal tool but anyway norton still doesn’t work , i’ve checked for virus, spyware , malware ecc… but still nothing , in my opinion is live update who creates all these problems beacuse all the problems starts after the updates (even if i’m not 100% sure) , who can i solve the problem? (ps my license ends in 2016) thanks