I don't think it's necessary to go through the registry.
If anything is left over you should be able to remove it from the device manager.
Same place you were before under "non-plug and play drivers" with the setting to "show hidden devices".
See this post by a Symantec employee:
http://community.norton.com/t5/Norton-360/Norton-Error-3043-1-on-Norton-360-v5/m-p/584264#M59330
Thats for Norton 360 but I see the same legacy drivers in the NAV 2013 I just installed:
Naveng
navex15
norton antivirus settings manager
norton identity safe
symantec data store
symantec iron driver
symantec network dispatch
symantec real time storage protection
symevent.
Those are the ones present for me, obviously they should be removed after uninstalling the product and running the norton removal tool.
Here is what I would do, if you choose to try this it will be at your own risk.
uninstall NAV, reboot, run the norton removal tool and reboot again.
run the symclean tool and reboot.
create a system restore point or registry backup
Serch for any of the above drivers in the device manager and remove them, answering NO to any prompt to reboot.
Any other drivers starting with Symantec must be leftovers from SEP.
I'm not sure about the firewall entry in your screenshot but I think I would delete that too.
I don't have that entry present but I did not enable IPv6 in XP before installing NAV.
Be very carefull deleting those drivers so you don't remove a necessary one by mistake.
Don't proceed if you get a warning about windows needing it to boot.
I know you will not have any problems by removing the files that subash listed.
After you reboot, before you reinstall NAV, Iook in the registry for a couple things.
I'm going to send you the registry keys in a private message because posting them my be frowned upon.
Click the envelope icon on the top right in a few minutes.
Dave