Hannah, this is NOT for you. At least, not yet. At the moment, you should be following tony Weiss' instructions.
This is for the team.
We all know that a full reformat (high level) should clear the entire hard drive (that means ALL PARTITIONS). And even without zeroing the artifacts, there really should be nothing problematic when reimaging the hard drive.
There are only two things that haven't been explored - one of which has already been hinted at.
1. The bios themselves contain something that is viral in appearance if not reality. I've never seen this; but I suppose it is possible.
2. The recovery CD's contain something that is viral in appearance or reality.
For the moment just consider option 2, the recovery CD's (or DVD). Contemporary computers almost all have a hidden partition containing the software for reimaging the hard drive. Some of the contents are not viral, but put your computer at risk -- software like earlier versions of Flash or Shockwave or Adobe Reader or Real Player or Java. If you run a "risk-detector" like Secunia it finds those programs. You aren't really at risk because you are no longer using them, but you are momentary at risk any time you reimage your harddrive -- those programs need to be upgraded (and sometimes uninstalled by hand).
Now what if at the time Hannah's computer was being "built," there was a piece of malware not recognized as such and it was included in her package. Not at all unlikely, based on my experience. Or a piece of out-of-date software that was once considered viral but is now recognized as safe, but which Norton never made an adjustment for.
If it's the latter possibility, then that might explain similar complaints in a number of other threads -- all users who are being warn of virus at a deep level that no other AV program finds. In order to discover whether this is the case or not, Norton would be a copy of Hannah's recovery disks to image a computer for testing. Perhaps the manufacturer would be willing to work with Norton to explore the issue. It would be for everyone's benefit.
If it's the former possibility, then the suggestion made earlier is really vital. Stop using recovery CD's. Instead:
1. Don't just reformat the harddrive. Remove all the partitions, too, as part of the reformatting.
2. Install windows from a CD.
3. Get the updates from Windows Update, opting for SP3 as soon as it is offered.
4. Install the Norton AV2009 or NIS2009 and run a full scan.
If the computer gets a clean bill of health, a lot has been established: no physical problems with the computer, no problems with Windows, no interactive problems with Windows or Norton. If the computer is said to have a virus, this is "impossible," which only means there is a physical flaw in the computer, or the Windows installation disk is defective, or the Norton installation software is corrupt. (This is if we have ruled out BIOS as a problem.)
If there is no problem, Hannah could then use the product recovery disks to put in the particular drivers necessary for her computer, a couple at a time, checking every so often with Norton to see if there is yet any problems. And then do the same thing with the software.
Does anyone at all have any problem with this strategy if Tony's advice doesn't help and if Hannah is open enough to explore it? Note that if there are things you want Hannah to do different than this, nothing about this will stop her ... afterwards. This process will only answer some fundamental questions that aren't yet being answered.