Thx for your answer, Peter.
That NPE can give false positives, was new to me. That would explain it. Because those files were all present during several previous versions of NPE I ran over the last 18 months. And then they were never considered to be a problem and/or suspicious. Btw: it is not that I run NPE all the time; only once every 2 or 3 months. Just to be on the safe side and to make sure NAV has not missed anything.
What I mean in my first post with "root sector", is ofcourse the boot sector (a.k.a. master boot record) of the hard drive.
Should be obvious, but it cannot hurt to clearify.
I hope someone can tell me if NPE (or NAV for that matter) scans the boot sector of all hard drives that are present, or only the one containing the Windows installation.