How can I add or delete buttons, images, pages, activities to the gallery?
You can add them by right-clicking on the activity in the tree and then choose Save .. to Gallery. Deleting cannot be done in the gallery but in Windows explorer. The default location is C:\Documents and Settings\All Users\Application Data\Philips\ProntoEdit Professional 2.0\Gallery (XP) or C:\ProgramData\Philips\ProntoEdit Professional 2.0\Gallery (Vista).