Here’s how to check, uncheck, enable, and disable a checkbox in MFC:
CButton* pBtn = (CButton*) GetDlgItem(IDC_SETUP_AM); pBtn->SetCheck(0);// uncheck it CButton* pBtn = (CButton*) GetDlgItem(IDC_SETUP_AM); pBtn->SetCheck(1);// check it CButton* pBtn = (CButton*) GetDlgItem(IDC_SETUP_AM); pBtn->EnableWindow(0);// disable it CButton* pBtn = (CButton*) GetDlgItem(IDC_SETUP_AM); pBtn->EnableWindow(1);// enable it