Step 1
Open your photograph.
Step 2
From Layers Palette, go on Channels, and click on icon like it is shown on the picture below.
Step 3
Now, we'll create our window :)
Take the Rectangular marquee tool and create the selection like it is shown on the picture below.
After that, fill it with white color.
Step 4
Then, press and hold down Ctrl + Alt + Shift key, and by mouse, move the selection from the left side to the right. Look at the picture below!
Step 5
Take again the R. M. tool and now, select the both "white rectangle" and copy them beneath. See the picture below.
If necessary, move the "window" on the center.
Step 6
Go on Filter - Distort - Shear, and apply it on "window" with the following settings.
Step 7
Then, press Ctrl + T key to rotate the window a little.
Step 8
After that, go on Edit - Transform - Distort, and try to get a realistic 3d preview. See the picture below.
We will also apply the blur filter to get a smooth light. So, go on Filter - Blur - gaussian Blur and apply the following settings:
Step 9
Press Ctrl+A key (Select all), and after that Ctrl+C key, to copy everything that we have selected.Then, go back on windows layer and click on our layer to activate it.
After that press Ctrl+V key. While the shadow layer is still selected, for Blending mode select the Overlay. See the picture below.
If the light is so intensive, you can always decrease the opacity.
More Tutorials: 
