Turn Auto-protect On - but it wont let me

Norton tells me 1 item is needing urgent attention. Turn Auto-Protect On. Fix Now. I click Fix Now and it 'fixes' for about 5 seconds before going back to 'Urgent Attention - Fix Now'.  My commputer is running slow, and some programmes are not working, like JavaScript.  Anyone any ideas? Is this a virus or a Norton fault? I am running a full system scan as I write this.... Any help would be greatly appreciated. Thank you.