All programs, apps, whatever in the windows environment are objects. However version 7 of vb is expected to be fully OOP therefore am trying to get as much info on sub-classing and inheritance as possible, to see what advantages effects this will have on existing apps, and design requirements for new apps. Classes should have shown even the most ardent anit-OOP programmers the advantages of this approach, therefore sub-classing and inheritance are likely to hold even better benefits. Of course MS might just rethink what this stuff should mean, and set their own view on it.