When computer reboots, my Norton stops working!

Each time my system shuts down, my Norton stops working.  I have to run the up-grade NIS-UPGRADE-ESD-NoDefs-19-5-1-2-eEN and it starts to work again.  I get the critical message and have to run a scan whereupon Norton duly finds viruses on my system - started off at 5 - last time I ran it it only found 2. 

 

Is there something I can do to stop me having to "reinstall" every time I boot the machine? 

 

Many thanks

 

Kim Clark