If you are going to re-install Norton, Symantec will say to completely uninstall the program first. Make sure you run the updates and when it tells you reboot do it. Then run Liveupdate until you have all updates. If you still have problems check their web site.
http://www.symantec.com/techsupp/consumer.html
Situation:
You are preparing to install Norton AntiVirus (NAV). You want to know what to do to ensure a problem-free installation of the program.
Solution:
Before installing NAV, you should do the following to ensure a problem-free installation of the program:
1. Verify that the computer is virus-free.
2. Uninstall any other antivirus software program.
3. Uninstall any previous version of NAV. This includes any trial versions, or NAV itself if you are reinstalling the program.
4. Close all running programs before starting the installation
Situation:
While installing Norton AntiVirus (NAV) from the CD, either the installation screen appears and then disappears when you insert the CD or nothing happens.
Solution:
To correct this problem:
1. Disable or uninstall any other antivirus product besides NAV that might be installed.
2. Reinstall NAV in Safe mode. See the document for your version of NAV: