I use I Obit Maleware fighter, advanced system care and Vipre. I have not added or changed anything in I don't know how long. Scans have shown almost nothing...except there is some kind of tracking cookie which gets wiped and then comes back.
I will check to see if I am using plain text. Also, I will try that Win Explorer suggestion.
Do you think that having a fairly full internal HD would have any effect?