I'm Yehana Mccoy Internet technology expert since 2001. I write blogs on everything related to the internet. I advise to the organization over the use of antivirus software and others. Blog- http://antivirusactivation.over-blog.com
In this case, Norton antivirus blocking star-up file. Such a file is important while restarting or shutdown. You should check the compatibility of Norton software for your PC hardware. I’ve a laptop of Lenevo and the same issue cause when I install the webroot antivirus software.