
When I used Norton
,
If you need help to get rid from Norton, just let me know...

Yes, maybe a clean install could help (unless you had desinstalled Norton from your computer a few time ago... and do not have reformated your HDD after...

)
Why don't you follow another way:
1. Download avast! 4.1.289
2. Desinstall your actual version of avast (Control Panel).
3. Boot
4. Use
Avast Uninstall for complete desinstallation.
5. Boot
6. Install the downloaded 4.1.289 and see what happened.