Thanks for your input, Prozactive. I believe the Avast self-defense module wasn't implemented until v. 5x. Still, 4.8 likely has some sort of self-protection, and you have given me some good ideas should I encounter a problem replacing the vps file. Thanks also for the DB download link, I had forgotten about that. I can likely use my download manager (FDM) to painlessly acquire the latest DB instead of using the Avast interface. I think I'm good to go.