Nortons installation

Hello,


I am trying to download my nortons onto my computer and everytime i try it tells me it is installing and that i must restart my computer. I do this and then when it comes on again it does the same thing. I have had my laptop for about 3 months so it says it is deleting the trial nortons that comes with the computer. Please can you help me as i am worried my computer is going to get viruses as icant download the new nortons..