It's obvious that Norton Security is somehow locking the C: drive in such a way that it causes a system hang.
It may be the same locking mechanism that is not releasing Windows XP during Shutdown causing the system to hang or freeze in both cases.
It's there, just that by the time you get through half of the batter you end up throwing the thing away before you get to it.
Perhaps if you contacted Customer support and explained that your NAV expired in May, but you would like to continue with NAV, perhaps they can do something for you.
It's my personal data ON the computer that makes it uniquely mine, and this particular set of data has been mine continuously since about 1999 or so, despite me having some half dozen computers since then.