Nortin will not configure due to Mcafee

I have a Gateway computer with Vista. It had Mcafee security on it. I wanted Nortin Internet Security. I used the add/remove to get rid of the Mcafee and manually deleted the empty Mcafee folder in the program files. Checked using search and nothing Mcafee showed. The Nortin loaded great but will not configure. I know this is caused by something of the Macfee left in the computer. I was told this is a common problem when changing from Mcafee to Nortin. Does anyone know where the traces of the Mcafee are filed? If so, please tell me in simple terms and in a very step by step direction. Would very much appreciate the help.