File counts scanning result less than another anti virus

Dear All,

 

Without intending to compare wich on is the best, Why is my NIS 2012 (19.7.0.9) scan external my hard drive with a report files that has scanned less than another anti virus, for I.e with my NIS reported file scanned 36.031 files but with another anti virus reported 221.125 files ?, although i have set my NIS with the following configuration:

 

1. Heuristic Protection set to "Aggressive"

2. Scan Performance Profile set to "Full Scan"

 

Please advice me....

 

Tks & B/regards,