I wouldn't feel comfortable about altering anything on this list unless I knew it could be reversed. However, now that I have Avast on my system instead of Bit defender, the slowdown problem has disappeared. I am well impressed with the new version of Avast so I have purchased a two-year licence. I think I may have found a small bug however: when creating a task, initially after saving it, the task is still called "Unnamed", but after opening it up to edit it, the actual name given to the task is displayed. Has anyone else noticed this? It's only a minor thing, so I'm not going to make a fuss about it.