NIS 2010 - Norton Insight - Scanning question.

Hi:

 

I need to clarify some things.

 

If my system has over 1.2 Million files on it, then how does Norton Insight tell me that 85% are trusted, yet it takes over 2 hours for a Full System Scan to complete?

 

-Also-

 

The Norton Insight Network says that 2,330+ files are *Trusted* - How is it obtaining that figure?

 

Obviously, I have much more than that as mentioned above.

 

Is it just relying on it's own database of 67 Million files (and growing?)

 

Thanks.