NIS 2013 scans more files/folders than I have on my PC?

I've recently built a new PC running Win 7 Pro 64-bit.   I went to download NIS 2012 but it was no longer available so I wound up with 20.1.1.2 (2013?).    After installation, I immediately ran a full system scan.   The scan completed with 946,000 items scanned.   After 5 days of installing additional applications, I scanned again - 985,000 items scanned.   Three more days go by and my apps have all been installed and configured the way I like.   Just before I am about to use Norton Ghost to make a backup images, I run one more scan.   This scan (using same parameters as prior scans) only scans 228,000 items.   At this point, I am worried.   I run LiveUpdate for NIS 2013 and rerun the scan - 988,000 items scanned.

 

I then proceeded to make my backup image with Norton Ghost (2002).   After the backup is completed, I run another Full System scan - it only scans 228,000 items.   I immediatly rerun the scan 3 more times.   The first two rescans scan about 228,000 items.   The final rescan scans 1,032,000 items.    I finally wonder just how many files I have and go look at my hard drives.   I have a total of about 178,000 files in 30,000 folders.

 

Does anyone know how NIS is scanning almost 4 times the number of items that are on PC and why it is doing so intermittently?   I have concerns that if NIS can't tell how many files there are to scan, how can it possible protect them all?

 

Jonathan