This tutorial will teach you some basic and advanced techniques that will help you create an attractive Windows Vista wallpaper.
Open a new file with
1024x768 px and
72 dpi. Then paint it with the shown color’s code
171D37.

Select the next instrument

to draw an ellipse (the shadow).
Fill 0% on the layers.
Blending Options-Outer Glow 
Make a copy of the new drawn ellipse and place them the way it is demonstrated below:

Selecting the previous instrument, create now the basis for a voluminous sphere.