C++ Code for Screen Capturing

C++ Code for Screen Capturing

I need to write code which will do screen sharing like WebEx or Team
Viewer for Windows PC. The requirement is I don't have admin access and I
can not Install any application or software for this. I know below
technology but none of them is working for me. I have tried all sample for
this code project URL
http://www.codeproject.com/Articles/5051/Various-methods-for-capturing-the-screen
(1) GetDC(NULL) and BitBlt with SRCCOPY <= This will not capture
Transparent Window and It cause GDI hung (Just try drawing in Paint.. your
pencil stuck for some time when BitBlt operation performerd)
(2) GetDC(NULL) and BitBlt with SRCCOPY and CAPTUREBLT Option <= This will
hide Cursor when I call BitBlt Operation and also GDI Hung when BitBlt
Operation Performed.
(3) I also tried with DirectX using GetFrontBufferData.. This cause
Flicker of my Transparent Window.
(4) I tried with Windows Media API but this require Windows Media Encoder
to be Installed.
(5) I tried with Mirror Driver also but this require Driver to be
Installed with Admin Access.
Can any one please suggest API where without any Installation I can
capture entire screen and No flicker or GDI hung problem.
Thanks in Advance.....