Hello Antoni,
Do you mean that the organs you'd like to delete are actually installed within Hauptwerk itself currently, and that you'd like to remove them all from Hauptwerk itself? Or that you simply have installers for those organs saved on a drive (that isn't used by Hauptwerk itself), and you'd like to wipe that drive?
(It's only possible to have Hauptwerk organs installed within Hauptwerk itself on one drive at a time.)