PRB: ClassWizard Doesn't Bring in Proper Header File

   error C2504: 'CSocket' : base class undefined
   error C2504: 'CAsyncSocket' : base class undefined
					

     ...
     #include <afxsock.h>  //MFC support for Sockets
     ...
				

MORE INFORMATION

The header file, afxsock.h, contains the class definitions for CAsyncSocket and CSocket. If you are using these classes or any classes that are derived from these classes, you must make sure to include afxsock.h in your project. Also note that if you use AppWizard to start your project and select the Socket Support option on the fourth page of the wizard, you will automatically get afxsock.h inserted into your StdAfx.h file. In addition, you will get the function call, AfxSocketInit(), inserted into your project. This is very important because you must make a call to AfxSocketInit() if you want to use Sockets in your MFC application. This function is usually called from your InitInstance() method of your CWinApp derived object.

   BOOL CMyApp::InitInstance()
   {

        if (!AfxSocketInit())
        {
             AfxMessageBox("Socket Initialization Failed");
             return FALSE;
        }

        ...
   }