Did you have the Win 7 Internet Security 2012 Virus on your machine before you loaded Norton? I think it's the source of this problem. I'm having the same problem as you and the folks at Norton haven't been able to fix the problem.
After installing the Norton AV program on my son’s computer (Windows 7) it had the Norton error 5013,3 which indicates that the Base Filtering Engine (BFE) service was not running.
I suspected some virus buried deep in the system so I ran all kinds of virus scans from Windows Essentials program and other 3rd party companies. The scans did find two Trojan viruses that were eliminated.
I then tried Norton’s instructions of manually starting the BFE service. Using the Windows Services app I discovered that there was no BFE service. Using the export function within REGEDIT I made copies of the BFE service as well as the MPSSVC service using my second sons’ computer that was running fine. I then installed the BFE and MPSSVC services on the faulty computer and hoped that it would get BFE running.
Note: Be very careful using REGEDIT. Recommend backing up the Windows Registry before making changes.
When I tried to get BFE running a pop up indicated some ACCESS Denied. I then realized the virus corrupted or changed some security features.
I came across the following articles that provided the next steps to get the bloody BFE service running. http://blogs.technet.com/b/networking/rss.aspx. Start with the first article to give you an overview.