Basic MFC...Barebone

Single Doc Application:

class myWindow: public CFrameWnd
{
}

class myApp: public CWinApp
{
public:
BOOL InitInstance()
{
m_pMainWnd = new myWindow();
m_pMainWnd->ShowWindow(SW_SHOW);
return TRUE;
}
}

Dialog based Application:

class myDialog: public CDialog
{
}

class myApp: public CWinApp
{
public:
BOOL InitInstance()
{
myDialog dlg;
m_pMainWnd = &dlg;
INT_PTR nResponse = dlg.DoModal();
// handle return from dlg here
return FALSE; // NOTE: Program ended when the dlg is closed
}
}

m_pMainWnd is a member of CWinThread.