how to load gif image in background thread in my form

how to load gif image in background thread in my form References I am creating a form where I want to display a progress bar (image) when i click a button which load all images in a specific system drive. after all images loaded from the specified drive,i should close that progress bar image. for that i just visible true the image when the button clicked and then finally visible false the image after all images loaded.but the progress bar image not visible true when the system getting all images from the specified drive. can anyone help me how to do this....