The MFC Application Wizard places help-specific code into the message map in the frame window class implementation file, MainFrm.cpp.
To copy help-related code to your project
- Open the HasHelp project MainFrm.cpp file and your project's version of MainFrm.cpp. 
- Scroll to the Help-related code, delineated by the //global help commands comment, in the message map section of the HasHelp MainFrm.cpp file. 
- Copy this code, shown below, from the HasHelp MainFrm.cpp file, and paste into the same position in the message map in your MainFrm.cpp. - // Global help commands ON_COMMAND(ID_HELP_FINDER, CMDIFrameWnd::OnHelpFinder) ON_COMMAND(ID_HELP, CMDIFrameWnd::OnHelp) ON_COMMAND(ID_CONTEXT_HELP, CMDIFrameWnd::OnContextHelp) ON_COMMAND(ID_DEFAULT_HELP, CMDIFrameWnd::OnHelpFinder)- You have already seen how ID_HELP_FINDER and ID_CONTEXT_HELP are called. When the user presses F1, the framework calls ID_HELP and directly handles this command so long as the application contains help support. 
- Close the HasHelp project's MainFrm.cpp file, and save the changes to your project's MainFrm.cpp. 
See Also
Concepts
Adding HTML Help Context-Sensitive Help to an Existing MFC Application