Disabling CTRL, ALT + DEL

I have not come across any solution for this at all apart from a registry key in the registry that disables it but i am not sure where it lies. However i am using Windows XP Home Edition, Version 2004, Service Pack 2. Is there anyway i can disable it in VB, if so how? Also if there is a regsitry key that does, where is it located.

Thank You

Jenova

Found this at http://www.codeproject.com/win32/AntonioWinLock.asp

HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System\DisableTaskMgr: DWORD

Set it to 1 to disable Task Manager and 0 (or delete key) to enable it again.

(I've not tested this...)

There are many ways depending on what you want.

If you want to disable the key combination you change/create the following key:
"Software\Microsoft\Windows\CurrentVersion\Policies\System" DisableTaskMgr = 1

If you want to disable the task manager you could use this code

VB Code:

'Before you lock it, make sure the task manager isn't running
Open "C:\Windows\System32\taskmgr.exe" For Binary Access Read Lock Read Write As #1

TheBigB,

Thanks for your code it works great :). I was thinking of doing it through the registry way, however i only get this far.

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Settings

The rest of the directy specified by schoolbusdriver does not exist in my registry. Is it possible that this may located in another place?

Thanks for your help as well :wave:

Jenova

You may have to create the key. I 've just tried it. It brings up a messagebox telling you task manager is disabled (by your administrator!). Merge the attached reg file if you want to try it.

Did you make that key in VB? If so can i have the source :)

No, I just used a .reg file. (Just in case...) To create it, make a plain text file (with a .reg extension) containing:-

Code:

---

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"DisableTaskMgr"=dword:00000001

---

Double-click on it and you'll get a messagebox asking if you want to add it to the registry.

To remove it:-

Code:

---

Windows Registry Editor Version 5.00

[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"DisableTaskMgr"=dword:00000001

---

and do the same.

I could write a procedure to add/remove the key in VB, but someone else will probably beat me to it. Lots of API calls. I DO have it somewhwere. If nobody else has posted it before I find it.... :)

i dunno what you want these things for, but there is one slight side-effect on that registry method... the problem is that you need to reboot your system, or at least log off and on again

In a .bas module:-

VB Code:

Option Explicit
 
Public Declare Function RegCreateKeyEx Lib "advapi32.dll" Alias "RegCreateKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal Reserved As Long, ByVal lpClass As String, ByVal dwOptions As Long, ByVal samDesired As Long, lpSecurityAttributes As Long, phkResult As Long, lpdwDisposition As Long) As Long
Public Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Public Declare Function RegOpenKeyEx Lib "advapi32.dll" Alias "RegOpenKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, ByVal samDesired As Long, phkResult As Long) As Long
Public Declare Function RegSetValueEx Lib "advapi32.dll" Alias "RegSetValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, lpData As Any, ByVal cbData As Long) As Long         ' Note that if you declare the lpData parameter as String, you must pass it By Value.
 
Public Const REG_OPTION_NON_VOLATILE = 0       ' Key is preserved when system is rebooted
Public Const HKEY_CURRENT_USER = &H80000001
Public Const REG_DWORD = 4                      ' 32-bit number
Public Const ERROR_SUCCESS = 0&
 
Public Const STANDARD_RIGHTS_ALL = &H1F0000
Public Const KEY_QUERY_VALUE = &H1
Public Const KEY_SET_VALUE = &H2
Public Const KEY_CREATE_SUB_KEY = &H4
Public Const KEY_ENUMERATE_SUB_KEYS = &H8
Public Const KEY_NOTIFY = &H10
Public Const KEY_CREATE_LINK = &H20
Public Const SYNCHRONIZE = &H100000
 
Public Const KEY_ALL_ACCESS = ((STANDARD_RIGHTS_ALL Or KEY_QUERY_VALUE Or KEY_SET_VALUE Or KEY_CREATE_SUB_KEY Or KEY_ENUMERATE_SUB_KEYS Or KEY_NOTIFY Or KEY_CREATE_LINK) And (Not SYNCHRONIZE))

Form:- This is just the bare bones. Needs error handling.

VB Code:

Option Explicit
 
Private Sub Command1_Click()
   Dim RetVal As Long
   Dim keyhandle As Long
   Dim lretval As Long
 
   Const sNewKeyName = "Software\Microsoft\Windows\CurrentVersion\Policies\System"
   Const dwTaskMan = "DisableTaskMgr"
 
'Create and close it.
   RetVal = RegCreateKeyEx(HKEY_CURRENT_USER, sNewKeyName, 0&, 0&, REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, ByVal 0&, keyhandle, lretval)
   RetVal = RegCloseKey(keyhandle)
'Re-open it.
   RetVal = RegOpenKeyEx(HKEY_CURRENT_USER, sNewKeyName, 0&, KEY_SET_VALUE, keyhandle)
   RetVal = RegSetValueEx(keyhandle, dwTaskMan, 0&, REG_DWORD, 1&, 4)
   RetVal = RegCloseKey(keyhandle)
'Done. I've not put any no error checking here. It would be wise to check RetVal as you go along...
End Sub

If you need code to remove the key, it'll have to be tomorrow... ;)

I just tried it, TheBigB. Didn't have to do anything except create and delete the key to disable/enable. Maybe because I'm the only user - as admin ? Dunno :ehh:

if you email me I can send you an example project that takes control of the computer .. you click exit to gain control again .. anyway disables everything .. no registry stuff .. found the procs on the web and changed it to be reusable .. i also use the same code in a program which mimicks the desktop run in its own custom shell (not explorer.exe) and has the vbAccelerator.com menu code to create a Start Menu with Custom Programs .. i started writing a customized version of this also .. just havent finished yet .. lets you track programs you open, also shows the icons in its own system tray .. etc etc ..

The registry entry works great :). Thanks alot you guys that really helped. Thanks to you to schoolbusdriver. Would you be able to post the code to delete the key please?

Many thanks again guys

Jenova

:wave:

Quote:

---

Originally Posted by schoolbusdriver

I just tried it, TheBigB. Didn't have to do anything except create and delete the key to disable/enable. Maybe because I'm the only user - as admin ? Dunno :ehh:

---

whoops :p i was doing it in local_machine ;)

Why do you want to disable Ctrl+Alt+Del for?

Ok Jenova. Here we go. I've added some basic error checking and the facility to change the key's value rather than simply deleting it - although that's there too. I've tidied it up a bit (my original code archive was for strings, not 32-bit numbers...) - it might make a bit more sense now (or as much as any api can) Take a GOOD look at the WARNING! :eek2:

.bas module

VB Code:

Option Explicit
 
Public Declare Function RegCreateKeyEx Lib "advapi32.dll" Alias _
   "RegCreateKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, _
   ByVal Reserved As Long, ByVal lpClass As String, _
   ByVal dwOptions As Long, ByVal samDesired As Long, _
   lpSecurityAttributes As Long, phkResult As Long, _
   lpdwDisposition As Long) As Long
Public Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Public Declare Function RegDeleteKey Lib "advapi32.dll" Alias "RegDeleteKeyA" _
   (ByVal hKey As Long, ByVal lpSubKey As String) As Long
Public Declare Function RegDeleteValue Lib "advapi32.dll" Alias "RegDeleteValueA" _
   (ByVal hKey As Long, ByVal lpValueName As String) As Long
Public Declare Function RegOpenKeyEx Lib "advapi32.dll" Alias "RegOpenKeyExA" _
   (ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, _
   ByVal samDesired As Long, phkResult As Long) As Long
Public Declare Function RegSetValueEx Lib "advapi32.dll" Alias "RegSetValueExA" _
   (ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, _
   ByVal dwType As Long, lpData As Any, ByVal cbData As Long) As Long
 
Public Const ERROR_SUCCESS = 0&
Public Const HKEY_CURRENT_USER = &H80000001
Public Const REG_DWORD = 4
Public Const REG_OPTION_NON_VOLATILE = 0
 
Public Const KEY_QUERY_VALUE = &H1
Public Const KEY_SET_VALUE = &H2
Public Const KEY_CREATE_SUB_KEY = &H4
Public Const KEY_ENUMERATE_SUB_KEYS = &H8
Public Const KEY_NOTIFY = &H10
Public Const KEY_CREATE_LINK = &H20
Public Const STANDARD_RIGHTS_ALL = &H1F0000
Public Const SYNCHRONIZE = &H100000
 
Public Const KEY_ALL_ACCESS = ((STANDARD_RIGHTS_ALL Or KEY_QUERY_VALUE Or _
   KEY_SET_VALUE Or KEY_CREATE_SUB_KEY Or KEY_ENUMERATE_SUB_KEYS Or _
   KEY_NOTIFY Or KEY_CREATE_LINK) And (Not SYNCHRONIZE))

form

VB Code:

Option Explicit
 
Const sNewKeyName = "Software\Microsoft\Windows\CurrentVersion\Policies\System"
Const sDelKey = "Software\Microsoft\Windows\CurrentVersion\Policies"
Const sSubKey = "system"
Const dwTaskMan = "DisableTaskMgr"
 
Private Sub Command1_Click()
'Create the key and respective value.
   Dim RetVal As Long
   Dim keyhandle As Long
   Dim lretval As Long
 
'Create and close it.
   If RegCreateKeyEx(HKEY_CURRENT_USER, sNewKeyName, 0&, 0&, _
      REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, ByVal 0&, keyhandle, _
      lretval) <> ERROR_SUCCESS Then GoTo MakeKeyError
   RetVal = RegCloseKey(keyhandle)
'Open the new key.
   If RegOpenKeyEx(HKEY_CURRENT_USER, sNewKeyName, 0&, KEY_SET_VALUE, _
      keyhandle) <> ERROR_SUCCESS Then GoTo MakeKeyError
   If RegSetValueEx(keyhandle, dwTaskMan, 0&, REG_DWORD, 1, 4) _
      <> ERROR_SUCCESS Then GoTo MakeKeyError
   RetVal = RegCloseKey(keyhandle)
   Exit Sub
MakeKeyError:
   RetVal = RegCloseKey(keyhandle) 'Close the key if it end up here...
   MsgBox "Cannot create the key. Dunno why."
   Exit Sub
End Sub
 
Private Sub Command2_Click()
'Open the key and change its value.
   Dim RetVal As Long
   Dim keyhandle As Long
   Dim lretval As Long
 
'Open the key and change its value - the 5th parameter of RegSetValueEx - "0".
   If RegOpenKeyEx(HKEY_CURRENT_USER, sNewKeyName, 0&, KEY_SET_VALUE, keyhandle) _
      <> ERROR_SUCCESS Then GoTo MakeKeyError
   If RegSetValueEx(keyhandle, dwTaskMan, 0&, REG_DWORD, 0, 4) _
      <> ERROR_SUCCESS Then GoTo MakeKeyError
   RetVal = RegCloseKey(keyhandle)
   Exit Sub
MakeKeyError:
   RetVal = RegCloseKey(keyhandle) 'Close the key if it end up here...
   MsgBox "Cannot change the key. Dunno why."
   Exit Sub
End Sub
 
Private Sub Command3_Click()
'Delete the "system" key. Don't Panic....
   Dim RetVal As Long
   Dim keyhandle As Long
   Dim Response As Integer
   Dim Msg As String
   
'Delete the value.
   If RegOpenKeyEx(HKEY_CURRENT_USER, sNewKeyName, 0&, KEY_SET_VALUE, keyhandle) _
      <> ERROR_SUCCESS Then GoTo DelKeyError
   If RegDeleteValue(keyhandle, dwTaskMan) <> ERROR_SUCCESS Then GoTo DelKeyError
   RetVal = RegCloseKey(keyhandle) 'Close the key if it's got this far...
 
'WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING!
'IF THIS KEY CONTAINS VALUES OTHER THAN "DisableTaskMgr", THESE WILL BE DELETED TOO.
'UNLESS YOU WANT TO ENUMERATE THIS KEY FOR OTHER VALUES, BACK OUT WHEN PROMPTED!!!
'AN EMPTY KEY WILL NOT DO ANYONE ANY HARM.
 
'Delete the key.
   Msg = "Deleting the System key may result in eternal hell and damnation!!"
   Msg = Msg & " Are you ABSOLUTELY sure you want to do this?"
   Response = MsgBox(Msg, vbCritical + vbYesNo, "DisableTaskMgr deletion")
   Select Case Response
      Case vbYes
         If RegOpenKeyEx(HKEY_CURRENT_USER, sDelKey, 0&, KEY_SET_VALUE, keyhandle) _
            <> ERROR_SUCCESS Then GoTo DelKeyError
         If RegDeleteKey(keyhandle, sSubKey) <> ERROR_SUCCESS Then GoTo DelKeyError
         RetVal = RegCloseKey(keyhandle)
      Case vbNo
         MsgBox "A wise choice!"
         Exit Sub
      End Select
   Exit Sub
DelKeyError:
   RetVal = RegCloseKey(keyhandle) 'Close the key if it end up here...
   MsgBox "Cannot delete the key. It may have already been deleted."
   Exit Sub
End Sub

TheBigB, I'm sure I've read somewhere about needing to reboot too, but can't think where. It doesn't seem to make any difference when I try it. Oh well - it works! Time for coffee.... :wave:

Schoolbusdriver
You the man :D. Thanks alot, this is greatly apprreciated lol

Penegate
Just for general knowledge really. I have never seen a working example before.

Thanks for your help guys :wave:

Jenova

To all: please read the following article:

Trapping Special Key Events using Low Level Hooks

Quote:

---

Originally Posted by RhinoBull

To all: please read the following article:

Trapping Special Key Events using Low Level Hooks

---

it's known that hooking lowkeys is no longer possible in xp sp2

@Jenova: if your question is answered, please mark the thread resolved

Quote:

---

Originally Posted by TheBigB

it's known that hooking lowkeys is no longer possible in xp sp2

---

works for me ...

Quote:

---

Originally Posted by TheBigB

it's known that hooking lowkeys is no longer possible in xp sp2

---

A lowkey? :confused:

Quote:

---

Originally Posted by rory

works for me ...

---

weird.... . :ehh:

Try looking up the Kernal32 virus on Symantec.com, it does the same thing and the instructions to remove it should lead you right there.

Well im not finished yet so cant post the whole code .. but it goes a little something like this .. found this on the web a while ago.

on The Form ..

VB Code:

Private Sub Form_Load()
    Call EnableWindows(False, Me.hwnd)
    Call SetHook
End Sub
 
Private Sub Form_Terminate()
    Unload Me
End Sub
 
Private Sub Form_Unload(Cancel As Integer)
    WindowsEnabled = True
    Call EnableWindows(True, Me.hwnd)
    Call UnSetHook
    End
End Sub

And a very small part in the module is like this ..

VB Code:

'This will prevent the task manager from appearing
'when the user presses Ctrl+Alt+Del. This will also disable the
'Alt+Tab and the Ctrl+Esc key combinations.
Public Sub AntiTaskManagerController(Enabled As Boolean)
    On Error Resume Next
    If IsWinNT Then
        Call NTController(TASK_MGR, Enabled)                                'control the task manager in registry
        If Enabled Then
            Close #1                                                        'Close the Taskmgr.exe, so we can run task manager normally
        Else
            Dim TMHwnd              As Long
            Dim ProcID              As Long
            Dim ProcessName         As Long
            Dim retVal              As Long
            
            'If task manager opened we closed it first as we can't open an opened file
            TMHwnd = FindWindow("#32770", "Windows Task Manager")           'Find the HWnd of task manager
            retVal = GetWindowThreadProcessId(TMHwnd, ProcID)               'Find the process id
            ProcessName = OpenProcess(&H1F0FFF, 0&, ProcID)                 'Open the process
            retVal = TerminateProcess(ProcessName, 0&)                      'Terminate it back
            Open Environ("WinDir") & "\System32\Taskmgr.exe" For Input Lock Read Write As #1
        End If
    Else
        SystemParametersInfo 97, Enabled, Enabled, 0
    End If
End Sub
 
'This will enable or disable the windows task manager. Please note that
'this procedure does not work on any Non-NT based system (win 9x)
Public Sub NTController ( ByVal EnmPrivilage As EnumNTSettings, ByVal Enabled As Boolean)
    If Not IsWinNT Then Exit Sub
    Dim Command         As String   'holds the Value to open
    'Get the text to for the registry value for the selected setting
    Select Case EnmPrivilage
        Case CHANGE_PASSWORD: Command = "DisableChangePassword"         'Don't allow pasword change
        Case LOCK_WORKSTATION: Command = "DisableLockWorkStation"       'Disabling locking of workstation
        Case REGISTRY_TOOLS: Command = "DisableRegistryTools"           'Cancel the register tools, like regedit
        Case TASK_MGR: Command = "DisableTaskMgr"                       'Cancel task manager
        Case DISP_APPEARANCE_PAGE: Command = "NoDispAppearancePage"     'No Display properties page
        Case DISP_BACKGROUND_PAGE: Command = "NoDispBackgroundPage"     'No Background properties page
        Case DISP_CPL: Command = "NoDispCPL"                            'Don't Display CPLs
        Case DISP_SCREENSAVER: Command = "NoDispScrSavPage"             'No Screen saver any more
        Case DISP_SETTINGS: Command = "NoDispSettingsPage"              'No setting page any more
        Case Else: Exit Sub
    End Select
    If IsWinNT Then
        Call CreateRegLong(HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", Command, Not Enabled)
        If IsW2000 Then Call CreateRegLong(HKEY_CURRENT_USER, _
       "Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\LocalUser\Software\Microsoft\Windows\CurrentVersion\Policies\System", _
         Command, Not Enabled)
    End If
End Sub