How do I... Disable Control Alt Delete?

Post #9. Where is says it kills taskmgr if ctrl alt del is pushed

I took all the code from post number 9, copied it into a new project and ran it...

but it does nothing....

It doesn't work unless you build it and run it the .exe from the release folder. It works pretty well.

ok I will try

sorry Man, still doesn't prevent the task manager at all on my system... ctrl+alt+delete works just fine, and it doesn't get closed either...

Hmm.. That's weird. It works great on mine. I created a form the size of my screen, made it always on top and hide my taskbar and put that code in there. I d/l a list of shortcut keys and it blocked them all. I ended up having to reboot to get back out of it because I forgot to add a exit button.

how do you log onto windows XP? Do you use that weclome screen? or do you use the traditional login method where user name and password has to be typed?

Are you using XP Pro or XP Home?

Often times these types of differences will change the behavior of ctrl+alt+delete.

For example, on XP home when you ctrl+alt+delete you simply get the taskmanager.

On my system, I get the windows security dialog.

XP Pro. I get the Windows Security Dialog also but when I click on task manager on that dialog it kills the task manager.

well, as you can see from my screen shot, it doesn't close mine.

I'm not trying to fool anyone here... I would be more than happy to see real ctrl+alt+delete blocking code, but this code doesn't do ANYTHING that I can see when I run it. I compiled and ran the exe from windows in release mode just as you said.

That is kinda weird, but as you see there's no problem detecting a Ctrl Alt Delete combo.
It's not a problem to kill the task manager quickly.

kleinma, it does seem like you're making it out to be some mythical legend perhaps to dissuade people from using it. No big deal either way.

The task manager kill procedure, is on a timeout.
Set it a little higher.
I believe you can also create, and/or use this registry setting for that.
HKEY_CURRENT_USER > Control Panel > Desktop > LowLevelHooksTimeout

no, I am just saying that I haven't seen any VB code to actually do it and have it work on my system.

If you can give me code to do it fine, but now its sounding a bit silly, all sorts of registry hacks and such to try to make it work? I'm not going to go screwing around with my system to try to get it to work, when with the default settings my system is using now, it doesn't work.

Maybe it works on some systems, but it obviously isn't fool proof...

Quote:

---

no, I am just saying that I haven't seen any VB code to actually do it and have it work on my system.
If you can give me code to do it fine, but now its sounding a bit silly, all sorts of registry hacks and such to try to make it work? I'm not going to go screwing around with my system to try to get it to work, when with the default settings my system is using now, it doesn't work.
Maybe it works on some systems, but it obviously isn't fool proof...

---

Maybe it works on most systems, especially those where one wants to have this function.

It's not a registry hack to Set it a little higher.
An advanced version would sync up to the registry setting.
Besides, you've already commited yourself here:

Quote:

---

I guarantee that any code you might put in your app to get around ctrl+alt+delete I could easily bypass.

---

If you're still game, we can do this offline sometime.

sure if you update the code to the "advanced" version, I will be happy to try it again on my system, as well as Vista if you like.

I am not bashing your code, or telling people not to use it. All I am saying is it doesn't work when I try it. I am not going to jump through hoops to figure out why, simply because I don't really care why it doesn't work.

If it did work, I would then try to circumvent it, and see if that was possible.

If I could not find a way around it, then I would concede and be more than happy to tell you I can't bypass it.

Until then I am just stating for the record that this doesn't work on my XP Pro machine, I am just saying it in case someone comes along and thinks they could copy/paste this code into their app and the end user won't be able to hit ctrl+alt+delete

If you are genuinely curious, try adding a little more time in the KillTaskManager loop. No fuss, no hoops to go through.

I'd be willing to withdraw questionable, or missusable submissions, but the codeguru seems to have no problem with it.

I am curious if this works on Vista, but I'd trust my own objective tests for that.

It may be easier to circumvent the code if you've gotten a chance to look at it up close. But what if you didn't?
I could circumvent it myself, in about five different ways back and forth.
I'm not sure if there is an end to it...
However there is no subjective guarantee either way, as you put it.
Did you make any changes to the code, or your system before trying it?
It looks a little like you have.

Quote:

---

Until then I am just stating for the record that this doesn't work on my XP Pro machine, I am just saying it in case someone comes along and thinks they could copy/paste this code into their app and the end user won't be able to hit ctrl+alt+delete

---

For the record this code works on everyone elses PC except yours. You are the first person, of at least a dozen others.

can someone build the executable for me as i am new at this so it stops ctrl+alt+del, ctrl+alt+esc, alt+F4 and win key

Quote:

---

Originally Posted by TTn

'Here is an example of how to SwapKeys.
'It's somewhat like SwapMouseButtons, but only for the keyboard.

Code:

---

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        HookKeyboard()
    End Sub
    Private Sub Form1_Closed(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Closed
        UnhookKeyboard()
    End Sub

    Public Function IsHooked(ByRef Hookstruct As KBDLLHOOKSTRUCT) As Boolean
        On Error Resume Next

        If Hookstruct.flags <> 128 Then 'Do this on key down only.  the flag for key up is 0.
            If Hookstruct.vkCode = Keys.A Then 'If a key is pressed
                apikeybd_event(Keys.Z, 0, 0, 0) 'press any key. (z in this example)
                Return True
            End If

            'Repeat this skeleton for any key, or combo!!! 
            'If Hookstruct.vkCode = Keys.A Then
            '    apikeybd_event(Keys.Z, 0, 0, 0)
            '    Return True
            'End If
        End If

        Return False
    End Function
    Public Structure KBDLLHOOKSTRUCT
        Public vkCode, scanCode, flags, time, dwExtraInfo As Int32
    End Structure
    Public Delegate Function KeyboardHookDelegate(ByVal Code As Int32, ByVal wParam As Int32, ByRef lParam As KBDLLHOOKSTRUCT) As Int32
    <System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.FunctionPtr)> Private callback As KeyboardHookDelegate
    Public KeyboardHandle As Int32
    Const HC_ACTION As Int32 = 0
    Const WH_KEYBOARD_LL As Int32 = 13
    Const VK_CONTROL As Int32 = 17
    Public Declare Function apiSetWindowsHookEx Lib "user32" Alias "SetWindowsHookExA" (ByVal idHook As Int32, ByVal lpfn As KeyboardHookDelegate, ByVal hmod As Int32, ByVal dwThreadId As Int32) As Int32
    Public Declare Function apiCallNextHookEx Lib "user32" Alias "CallNextHookEx" (ByVal hHook As Int32, ByVal nCode As Int32, ByVal wParam As Int32, ByVal lParam As KBDLLHOOKSTRUCT) As Int32
    Public Declare Function apiUnhookWindowsHookEx Lib "user32" Alias "UnhookWindowsHookEx" (ByVal hHook As Int32) As Int32
    Public Declare Sub apikeybd_event Lib "user32.dll" Alias "keybd_event" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Int32, ByVal dwExtraInfo As Int32)
    Public Sub HookKeyboard()
        callback = New KeyboardHookDelegate(AddressOf KeyboardCallback)
        KeyboardHandle = apiSetWindowsHookEx(WH_KEYBOARD_LL, callback, System.Runtime.InteropServices.Marshal.GetHINSTANCE(System.Reflection.[Assembly].GetExecutingAssembly.GetModules()(0)).ToInt32, 0)
    End Sub
    Public Sub UnhookKeyboard()
        If KeyboardHandle <> 0 Then apiUnhookWindowsHookEx(KeyboardHandle)
    End Sub
    Public Function KeyboardCallback(ByVal Code As Int32, ByVal wParam As Int32, ByRef lParam As KBDLLHOOKSTRUCT) As Int32
        If Code = HC_ACTION AndAlso IsHooked(lParam) = True Then Return 1
        Return apiCallNextHookEx(KeyboardHandle, Code, wParam, lParam)
    End Function

---

---

Hi TTn,
Is this VB6, as i am getting lots of RED lines while pasting this code in VB6....:eek:

Quote:

---

Originally Posted by PriyankaB

Hi TTn,
Is this VB6, as i am getting lots of RED lines while pasting this code in VB6....:eek:

---

Oops! Sorry, i was searching in VB6 thread and never knew how n when i entered in this .Net thread.