|I agree, you hard disk is in the way out and will soon need to be replaced.|
Modern hard disk have an area set aside by the manufactures to automatically remap bad sectors when they occur. This happens invisible to the user. Once this area is full, then any more bad sectors need to be excluded by an external application like scan-disk.
So even though scan-disk has identified 7 bad sectors there are others that you don't know about and once bad sectors start appearing, you can be sure there will be more to follow.
Bad sectors are caused by the deterioration of the magnetic coating of the hard disk with time. It will happen with all hard disk eventually is something else doesn't kill them like a worn drive spindle or a failed voice coil. It is the voice coil that controls the head movement.
Time to go shopping.