Thank you all for the clarification and the link.
I defragment manually once a week, I don't want to do the scheduled one, because I am afraid that it will defragment my SSD-HD, which I don't want done.
I know there is a choice, which HDs to do, (I have it done on my other PC like that), but I don't trust it.
Again, many thanks for taking your time to answer.
All the best in 2013.