You are not done testing yet unless…you have checked the following points for each and every dialog box in your application:
Verify that the correct system controls display on the title bar (e.g., some dialog boxes can be maximized while others cannot) and work correctly.
Verify that the default edit-focused control and default button-focused control are correct.
Verify that the dialog can be canceled by
Pressing the Escape key (regardless of which control has focus)
Pressing the system close button (the 'x' button on Microsoft Windows dialog boxes)
Pressing the cancel button on the dialog
Verify that the dialog can be closed and its contents accepted by
Pressing the Enter button (regardless of which control has focus, although multi-line text boxes may need an exemption)
Pressing the accept or OK button on the dialog
Verify that the keyboard navigation order is correct. (Microsoft Windows apps often refer to this as "tab order" as the convention on that operating system is that pressing Tab moves you through the dialog box.)
Verify that every control has a shortcut letter, that every shortcut works, and that each shortcut is unique within the dialog box.
Verify that each control's tooltip is correct.
Verify that any mutually exclusive controls work together correctly.
Verify all dialog states, such as different sets of controls being visible due to application state or "more details" and "less details" buttons on the dialog box being invoked.
Verify that all ninchable controls (controls which can be in an indeterminate state; for example, the Bold button would be ninched if the current selection contains some text that is bolded and some text that is not bolded) do in fact ninch as appropriate.
Verify that editing a ninched value has the correct effect (i.e., applies the new value(s) to all items which should be affected; to revisit the text example, all text should be bolded).
Verify that each control responds correctly to valid input and invalid input, including appropriate boundary cases. For example, invalid input might cause a message box to be displayed, or highlight the control in some fashion.
Verify that the dialog displays and functions correctly
With different color settings
With different font settings
In high contrast mode
In high DPI mode
Verify that all images and other media in the dialog box are localized correctly.
