I admit I'm not the most diligent scanner and I don't use a scheduled scan because 1) I turn my computer off at night and 2) scans slow my computer badly.
That said, on 10-Sep-2010 I deep-scanned my computer and the log reported 991,208 files scanned, 299,554 Scanned archives and a scan time of 02:57:14.
My next deep scan was on 11-Oct-2010 and the log reported 1,729,449 files scanned, 631,964 Scanned archives and a scan time of 05:03:53.
That is an increase of over 800,000 files, 330,000 scanned archives and 2 hrs of scan time.
Both scans reported only one threat, a TV Guide cookie.
I have no idea where all these new files are or where they came from.
On 11-Sep-2010 I installed Multitrack Stopwatch with a total of 10 files.
On 07-Oct-2010 I installed Foldit with a total of 3 files.
On 15-Oct-2010 I re-installed HijackThis which added 34 files, because I made a copy of the old version in a different folder.
On 15-Oct-2010 I installed the free COMODO firewall, 219 files, 109 of them language files and
On 17-Oct-2010 I installed 16 MS Windows updates (I'm a bit behind on these).
I checked through all the new files in Documents and Settings and they total about 900, none "archive" files.
How do I locate the 330,000 new "archive" files so I can see if they are necessary, if they are somehow duplicates, or if there is a good reason for their existance? I'm pretty sure that is where the bulk of the additional 800,000 files are.