Good day Tech and thanks a lot for responding. I want to add also that this problem only occurred yesterday(March 28, 2009) and just last week I did an on demand scan and Avast worked fine. As to 1)recent changes made: Just recently, because of the Conficker warnings, I'm changing all my passwords and running Firefox so that all private are erased after each session and also ran ccleaner and erased temporary files(only those older than 48 hrs). As to 2)other Security software: Since I had a reformat this January I only installed Avast, nothing else, although just yesterday, again because of this Conficker scare, I downloaded Sophos Conficker Remover(but not install), Windows Defender(but not install cause its incompatible with my OS) and Eset Conficker Remover(did not install but discarded it cause its only for Conficker A). Now Lastly to my OS: I still use MS XP Service Pack 1-Now I know you could tell me to update and all but here when I had the reformat most probably the technician who did this used pirated software and I have to say again it was working fine til yesterday.