Fill 0% on the layers.
Blending Options-Gradient Overlay

Create Microsoft Windows Vista Wallpaper in Photoshop CS

Gradient?s parameters:

Create Microsoft Windows Vista Wallpaper in Photoshop CS

We should copy again the new made layer three times and use Free Transform option to minimize
the copies.

Create Microsoft Windows Vista Wallpaper in Photoshop CS

Copy the earlier create layer of the lateral flare and make use of the Free Transform option to increase it a little this time.

Create Microsoft Windows Vista Wallpaper in Photoshop CS

Create Microsoft Windows Vista Wallpaper in Photoshop CS