I know since Directx 8 Microsoft join DirecDraw into Direct3d, that signifies that all I can do with DirectDraw now I can do it with Direct3d? Technically, DirectDraw is for compatibility with back versions. Thank.

There are still some things that are easier with directdraw that direct3d. Direct3d uses hardware acceleration though so many functions (Alpha) are quicker. Directdraw is still supported by directx but they ran out of things to add to it.

I still use directdraw for 2D tilemap type games, its much simpler to use and runs fairly quickly on a low spec machine.

,Jay

You can still use the older interfaces for DX, so you will be able to use DirectDraw 7 forever if you like.
The only problems here are that you have to find the documentation (it is no longer included in the download), and people at GameDev.Net will make fun of you.