Its not transparant, I just dont like the windows in ???windows??? as there all the same, so i make my own from scratch using bluegui and a Skinned Window system I made.
If you want a transparant part on a window then look up the command
SetGadgetShape, This will allow you to use a mask image to make part of a window or gadget transparant.
Alternativley if you do want to make a window my way, (Which i wouldn't recommend as it does use extra system resources, and you need to take manual control of window resizing and repositioning) then the window pictured above is created using about 30 borderless windows and Panels, all attached direct to the desktop to the shape of a window, the gaps are where as i just remmed out some panels, This way is much slower to do than just using a Mask Image and can be much more problamatic so i'd recommend you try using the SetGadgetShape option, (The window above took me 2 days to make using a Windows Media Player Skin).
Everyone Be Cool, You, Be Cool.