Selections, Invert, Hit the delete button on the keyboard OR go to Edit,Clear. Now all the black squares should be gone and you will see a white grid.
Selections, Invert again, and apply an inner bevel with the previous settings (effects,3d effects,innerbevel)
Add a new layer and name it fanblades. Selections - Load from disk - blades. Flood fill white. then Selections - Float.
Add an inner bevel (effects - 3d effects - inner bevel)
Deselect and Save.
Add a new layer - Fan middle.
Deselect. Move this circle with the mover tool to position right
in the middle of the blades.
Have you been saving your work?