Create a new document "1280x1204" (or your desired screen resolution). Color your background with a gradient using the colors #004061 and #006193.
Select your "elliptical marquee tool" and draw out a circle.
Now add these layer styles.
You should then end up with something like this.
Select your "elliptical marquee tool" again and draw another circle over the top just a little bit bigger than the 1st one, with it still selected goto "select > modify > contract" and contract it by 50 pixels (depending on how big your resolution is).
Now add these layer styles to it.
You should have something like this.
Now we need a windows logo i got mine from google images. Copy & paste your windows logo onto your canvas and position in the middle of your orb. (If your logo has a white background then just delete it with your preferred tool).
Now add these layer styles to the logo.
You should now have something like this.
Select your "elliptical marquee tool" again and draw out a circle at the top of your orb, color it white. Also set the opacity to 25%, Then mask the layer. You should end up with something like this.
Do the same again but draw out an even bigger circle, and set opacity to 20%. The result is in the image below.
That's it all finished here's my final result but I've added the text to the orb and some smaller orbs around it.
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