disable ctrl-alt-del



Hi everyone,

I'm looking for a way to disable the ctrl-alt-del key combination. I know
this can be done in gpedit.msc. However, I want to do it from within a
program I'm writing. On several websites I saw people suggesting changing
the registry keys DisableCAD or DisableTaskMgr, but this doesn't seem to do

Any suggestions on how to do this?


Doug Knox MS-MVP

To prevent users from opening Task Manager and killing processes. However, that doesn't address the other methods of doing the same thing.


I'm writing a secure windows shell, that can be used to restrict access to
the computer. For example if you're using a computer as an exhibition tool
you may want people to be able to run only one program. Unless you plan to
stay with the computer the whole time, you need a way to keep people from
starting other programs, shutting down the computer, killing processes,
browsing the hard disk, ...

My shell puts all that stuff behind a password. The system administrator
can then decide what programs the user is allowed to run.

Of course you might argue that creating a whole new windows shell is not
quite sane, but that's a different question completely ;)


If the question was/is "How to disable Task Manager" I can only rephrase:
Why does someone sane want to disable Task Manager? :blush:)


I won't argue the new shell questions :blush:) but running a computer in a kiosk
mode doesn't demand much effort.

Doug Knox MS-MVP

I can understand, but the typical use of CTRL-ALT-DEL, short of logging on, is to invoke Task Manager.


I cannot understand the use of CAD to invoke Task Manager :blush:). I teach
everyone to use CAD as shortcut to Lock Computer option only.

Doug Knox MS-MVP

If you're not in a domain environment, CAD will bring up Task Manager in a default installation. Winkey + L also locks the workstation.


I can see your point, but Win+L works in XP/2003 only. The same is true with
regard CAD, TM, and workgroup environment.


Jetro said:
I won't argue the new shell questions :blush:) but running a computer in a
kiosk mode doesn't demand much effort.

How would you go about running a computer in kiosk mode? Isn't there way
too much to take into account? As an example, the place where I used to
work had disabled registry editing. Good idea, except it was possible to
just create a .reg file and import that from the command line. If you
completely replace the shell there is not much anyone can do, no matter how
much they know about computers.

Doug Knox MS-MVP

If all you wanted was Internet Explorer, for example, you would set the Shell value on a per-user basis to run Internet Explorer in kiosk mode:

How to Use Kiosk Mode in Microsoft Internet Explorer

The Shell value is set/created in:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

You will need to be logged on to that account, when you change the value, or see www.dougknox.com, Win XP Tips, Advanced Registry Editing for a method of doing this while you're logged onto a different account, such as the Administrator.

You would then use TweakUI or CONTROL USERPASSWORDS2 to set the "internet only" account to autologon. Your Administrator account should still be enabled, and accessible via Remote Desktop (XP Pro only).

Additionally, you would want to enable various Internet Explorer restrictions, that prevent access to the file system from the browser and etc.


Doug Knox MS-MVP said:
If all you wanted was Internet Explorer, for example, you would set
the Shell value on a per-user basis to run Internet Explorer in kiosk

So then it does mean changing the shell. I do the same, only I use my own
program instead of internet explorer - which gives me a lot more options.

Doug Knox MS-MVP

Yes, if you put an alternate shell in place you can, very effectively, control what a user can/cannot do. My first effort at kid proofing a computer was to write an alternate shell for Windows 3.1. The kids could run 4 programs and nothing else.


How to disable Ctrl+Alt+Del in NT/2000/XP

There have been many people asking how to do this, so since someone
helped me find it, I figured I'd help any others that are looking for
this. The URL is:


The page explains what was done, how it was done, why it was done and
gives the source code to the DLL and sample apps for VB and C++.

Once you have the DLL in your project's path or in Windows\System32,
just call it using:

Private Declare Function CtrlAltDel_Enable_Disable Lib "WinLockDll.dll"
(ByVal bEnableDisable As Boolean) As Integer

Private Sub Command1_Click()
CtrlAltDel_Enable_Disable False '**** Disable use of Ctrl+Alt+Del End

Private Sub Command2_Click()
CtrlAltDel_Enable_Disable True '**** Enable use of Ctrl+Alt+Del End Sub

Enjoy all.

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