Sometimes it is necessary for a program to prevent the use of the CTRL+ALT+DEL key combination to bring up the Close Program task list to end a task or shut down Windows 95 and to prevent the use of the ALT+TAB key combination to switch tasks. The following technique uses the SystemParametersInfo API to trick Windows 95 into thinking that a screen saver is running. As a side effect, CTRL+ALT+DEL and ALT+TAB are disabled. The Win32 SDK states: "SPI_SCREENSAVERRUNNING Windows 95: Used internally; applications should not use this flag. Windows NT: Not supported." Note that disabling CTRL+ALT+DEL is not recommended because the Close Program dialog box was created to enable users to terminate misbehaving applications. If a program "hangs" while CTRL+ALT+DEL is disabled, it may not be possible to terminate it by any method other than rebooting the machine, which could result in the loss of data. You will need two command buttons for this program. Private Const SPI_SCREENSAVERRUNNING = 97& 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 Sub Form_Load() Command1.Caption = "Disabled" Command2.Caption = "Enabled" End Sub Private Sub Form_Unload(Cancel As Integer) 'Re-enable CTRL+ALT+DEL and ALT+TAB before the program terminates. Command2_Click End Sub Private Sub Command1_Click() Dim lngRet As Long Dim blnOld As Boolean lngRet = SystemParametersInfo(SPI_SCREENSAVERRUNNING, True, _ blnOld, 0&) End Sub Private Sub Command2_Click() Dim lngRet As Long Dim blnOld As Boolean lngRet = SystemParametersInfo(SPI_SCREENSAVERRUNNING, False, _ blnOld, 0&) End Sub Press the F5 key to run the program, and click the "Disabled"CommandButton. CTRL+ALT+DEL and ALT+TAB and CTRL-ESC are disabled. Click the "Enabled" CommandButton to enable CTRL+ALT+DEL and ALT+TAB and CTRL-ESC again.