NIS 2010 very long scan

I just did a scan of my "C" drive.  I have 2 hard drives but the FSS seems to be very long so I thought I would try only C to see how long it takes.  It took 1 hour 46 min to scan nearly 187,000 files.  On my other computer with the same software it scanned nearly 201,000 files in 18 minutes.  I did an uninstall, reinstall yesterday hoping it would make a difference but it did not.  This is not a huge number of files to scan.  My trusted level is about 84%.

 

Why does it take so much longer with less files?  Is there something I should check?  Is the trusted level just for quick scan or also FSS? 

 

Thank you for any replies.