Как заблокировать сочетания клавиш Ctrl+Alt+Del и Alt+Tab

Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, lpvParam As Any, ByVal fuWinIni As Long) As Long Private Const SPI_SCREENSAVERRUNNING = 97& Public Sub AllowKeys(bParam As Boolean) Dim lRetVal As Long, bOld As Boolean lRetVal = SystemParametersInfo(SPI_SCREENSAVERRUNNING, bParam, bOld, 0&) End Sub Private Sub Form_Load() Call AllowKeys(True) 'блокировка сочетаний End Sub Private Sub Form_Unload(Cancel As Integer) Call AllowKeys(False) 'разблокировка сочетаний End Sub

Const SPI_SCREENSAVERRUNNING = 97 Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" _ (ByVal uAction As Long, ByVal uParam As Long, ByVal lpvParam As Any, ByVal fuWinIni As Long) As Long Private Sub Command1_Click() Call SystemParametersInfo(SPI_SCREENSAVERRUNNING, True, "1", 0) End Sub Private Sub Command2_Click() Call SystemParametersInfo(SPI_SCREENSAVERRUNNING, False, "1", 0) End Sub Private Sub Form_Unload(Cancel As Integer) Call SystemParametersInfo(SPI_SCREENSAVERRUNNING, False, "1", 0) End Sub