How to Disable CTRL+ALT+DEL Key

CTRL+ALT+DEL is a low level Windows function, so I don't know of any good way to disable it, other than replacing part of the Windows system.

Why do you need to change the way Windows works?

You cannot disable Ctrl-Alt-Del from your application code, not even with a low-level keyboard hook. The reason is because C-A-D is part of Windows security system, NOT part of any user-mode application.

There are ways of doing it, but, like Walt said, you have to replace certain Windows libraries to do it. This is not something any user-mode code is going to be able to do.

No, I'm going to tell you how to do it because there is never a good reason to disable the key combination.

As walt said CTRL+ALT+DEL is a low level Windows function.....the only possible way is the uses of Global Hooks And Libraries.....Example

Lock Windows Desktop[^]

Thanks everyone 4 your contribution 'cos they set me thinking. I have found a way around it and that is setting the 'DisableTaskmgr' value to true in the Registry.
Here is how I was able to accomplish that:

To disable Taskmanager:

Private Sub DisableTaskManager()
    Dim regkey As RegistryKey
    Dim keyValueInt As String = "1"
    Dim subKey As String = "Software\Microsoft\Windows\CurrentVersion\Policies\System"
    Try
        regkey = Registry.CurrentUser.CreateSubKey(subKey)
        regkey.SetValue("DisableTaskMgr", keyValueInt)
        regkey.Close()
    Catch ex As Exception
        MsgBox(ex.Message, MsgBoxStyle.Critical, "Registry Error!")
    End Try

End Sub

To Enable TaskManager

Private Sub EnableTaskManager()
    Dim regkey As RegistryKey
    Dim keyValueInt As String = "0"    '0x00000000 (0)
    Dim subKey As String = "Software\Microsoft\Windows\CurrentVersion\Policies\System"
    Try
        regkey = Registry.CurrentUser.CreateSubKey(subKey)
        regkey.SetValue("DisableTaskMgr", keyValueInt)
        regkey.Close()
    Catch ex As Exception
        MsgBox(ex.Message, MsgBoxStyle.Critical, "Registry Error!")
    End Try

End Sub

Thanks and I hope everyone will find this code snippet useful.