Finally, I found it !! This code detect and cancel user input: Control+Esc void CMainFrame::OnActivate(UINT nState, CWnd* pWndOther, BOOL bMinimized) { CFrameWnd::OnActivate(nState, pWndOther, bMinimized); if(nState==1) return; BOOL bCtrlDown = (!(GetKeyState(VK_CONTROL)==0)); if(bCtrlDown) { // Wait for init Sleep(300); // Send cancel keybd_event( VK_ESCAPE,0,0,0 ); keybd_event( VK_ESCAPE,0,KEYEVENTF_KEYUP,0); // Send task change keybd_event( VK_MENU,0,0,0 ); keybd_event( VK_ESCAPE,0,0,0 ); keybd_event( VK_ESCAPE,0,KEYEVENTF_KEYUP,0); keybd_event( VK_MENU,0,KEYEVENTF_KEYUP,0); } } Emi