I do use O&O and the meaning of defragging is this.
Defragging (defragmenting) moves the files back together and in a particular order to make it work more efficiently. So if you could be more precise, are you saying that Avast does not need to work as efficiently as my other programs, so why would they get to a fragmented state anyway.
Do not be patronising in your replies please. I came to seek an answer to a question.