scenario: user 1 is presenting his or her desktop to user 2. user 2 can view what's happening on user 1 on his(user2)'s screen, but cannot control it.
got a hint from somewhere that by embedding activex control rdp will allow me to do so but i do not know where to start?
is this sort of like collaboration?
any help would be greatly appreciated ! thanks in advance !
The rdp control won't help you here. Rdp doesn't allow screen sharing. Remote assistance and "windows desktop sharing" (only in vista and newer) give you the core functionality but you will néed to adapt your solution on top of closed and poorly documented components.
Your best bet is probably to write something on top of vnc. Ultravnc's code is a mess, you will probably have better luck with tightvnc.
Good luck!