I managed to delete the OS off my BB. Several factors played a part- first, I have trigger fingers and click before reading. Second, my pc had a service pack loaded for the windows XP and it disagreed with my OS ver 4.0 upgrade. Thirdly (the real doozie), I tried to load a program onto the device and instead of keeping all the programs "clicked" I de-selected each of them which REMOVED them from the unit. Brilliant.
Thanks again to this forum- it's amazing!