I had/have the same problem, but I'm running ZoneAlarm, so I
set it to 'never allow rundll32 to access the internet' and
now I don't get bothered any more.
Can you do the same with Norton?
I believe that Western Digital has a hard drive testing
program available. A friend of mine ran it againt his
hard drive and it turned up so many bad clusters that
WD replaced it for the cost of shipping.