develop an active desktop control in c#

Since you want to do this using c#, Active Desktop is the wrong method.

You should create a form, and set the background color as the transparency colour, then set the form to always be at the background. Finally whyn you add controls they will appear as if they are floating on your desktop.

I have used a similar approach on a little project that is available somewhere on my website (linked in my profile).
If you want a form template creating for this, post back, and i'll see what i can do!

Alternatively... you can get a handle to the desktop window, from which you can create a GDI bitmap to draw on. There are API functions to do all this, which i can list for you if you want to give it a try.
This method will give you freedom to control exactly what you want to draw, but really isnt worth the effort, and is much much harder than a transparent form.

thanks for your answer,
i looked it your site and didnt found it.
can you send me the form template?
i tried to make a transperetn form before but the problem is it makes the text transperent two (and i want it to remain solid black)
did you handle it in your template?

I almost forget... there are probly a few other bits and bobs needed to make the illusion complete, such as setting the form not to display a taskbar, and adding an area where you can allow the user to re-position the window. apart from that, it should be

thanks i will check it on sunday and then i will accecpt the answer.