What is PV?
I can say that PV is a program like Microsoft Spy++. Unlikely to Spy++ it allows you to edit some properties of the Controls and also allows you to manage its window messages. You can change Text, Visibility, Enabled, Window Styles and Window Ex Styles properties of a control by using PV during run time. There withal you can ignore window messages, change incoming message to a different message or edit parameters of any window messages by putting breakpoints to the control’s window procedure with PV.