disable ctrl+alt+del

[shukla]

how to disable desktop and ctrl+alt+delete in vb.
i have a code but it applies only for windows-98 not for 2k and other.

[HanneSThEGreaT]

What code do you have ¿

Is your code using the SystemparametersInfo API ¿

[djklocek]

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.

Thanks to ALL API

[Rob123]

Try this out:

Private Function blockTaskManager(Optional disable As Boolean = True) As Boolean
On Error GoTo Fail
Static fileNumber As Integer
If disable Then
    fileNumber = FreeFile
    Open "C:\WINDOWS\system32\taskmgr.exe" For Random Lock Read Write As #fileNumber
Else
    Close #fileNumber
End If
    
blockTaskManager = True
Exit Function
Fail:
blockTaskManager = False
End Function
 
Private Sub Command1_Click()
'Block task manager
blockTaskManager
End Sub
 
Private Sub Command2_Click()
'Unblock it
blockTaskManager False
End Sub

[HanneSThEGreaT]

You guys beat me

I have a little simplified implementaion of SystemparametersInfo, for anyone who's interested

Private Declare Function SystemParametersInfo _
Lib "user32" Alias "SystemParametersInfoA" _
(ByVal uAction As Long, ByVal uParam As Long, _
ByVal lpvParam As Any, ByVal fuWinIni As Long) As Long 'API Function to disable keys
 
Private Sub DisableCtrlAltDel(bDisabled As Boolean)
 
   ' Disables Control Alt Delete Breaking
   'as well as Ctrl-Escape
   
   Dim X As Long
   X = SystemParametersInfo(97, bDisabled, CStr(1), 0)
 
End Sub
'useage
 
Call DisableCtrlAltDel(True) 'disable the system keys
'or
Call DisableCtrlAltDel(False) 're-enable the system keys

[RobDog888]

Try this out:

Private Function blockTaskManager(Optional disable As Boolean = True) As Boolean
On Error GoTo Fail
Static fileNumber As Integer
If disable Then
    fileNumber = FreeFile
    Open "C:\WINDOWS\system32\taskmgr.exe" For Random Lock Read Write As #fileNumber
Else
    Close #fileNumber
End If
    
blockTaskManager = True
Exit Function
Fail:
blockTaskManager = False
End Function
 
Private Sub Command1_Click()
'Block task manager
blockTaskManager
End Sub
 
Private Sub Command2_Click()
'Unblock it
blockTaskManager False
End Sub

That disables the task manager when the thread poster wants to disable the Ctl+Alt+Del keypress combination. It brings up the windows Security dialog.

[Rob123]

Ah yeah, never thought of that, don't have the dialog on this comp

[swcreator]

this will disable Ctrl Alt Del as long as your app is running

Private Sub Form_Load()
Open "C:\Windows\system32\taskmgr.exe" For Random Lock Read As #1
End Sub

[kleinma]

swcreator, that looks like VB6 code first of all, and second of all, all that does is prevent the taskmanager from being opened. It doesn't disable ctrl+alt+delete

[swcreator]

you can also make chance in register


Place to following code in a module:

Private Declare Function RegOpenKeyEx Lib "advapi32" Alias "RegOpenKeyExA" ( _
    ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, _
    ByVal samDesired As Long, ByRef phkResult As Long) As Long
 
 
Private Declare Function RegQueryValueEx Lib "advapi32" Alias "RegQueryValueExA" ( _
    ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, _
    ByRef lpType As Long, ByVal lpData As String, ByRef lpcbData As Long) As Long
 
 
Private Declare Function RegCloseKey Lib "advapi32" (ByVal hKey As Long) As Long
  
 
Private 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
 
 
Private Declare Function RegCreateKey Lib "advapi32.dll" Alias "RegCreateKeyA" ( _
    ByVal hKey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
 
 
 
Public Const HKEY_CLASSES_ROOT = &H80000000
Public Const HKEY_CURRENT_USER = &H80000001
Public Const HKEY_LOCAL_MACHINE = &H80000002
Public Const REG_SZ = 1
Public Const REG_BINARY = 3
Public Const REG_DWORD = 4
Public Const REG_OPTION_NON_VOLATILE = 0
Public Const SYNCHRONIZE = &H100000
Public Const READ_CONTROL = &H20000
Public Const STANDARD_RIGHTS_READ = (READ_CONTROL)
Public Const KEY_QUERY_VALUE = &H1
Public Const KEY_ENUMERATE_SUB_KEYS = &H8
Public Const KEY_NOTIFY = &H10
Public Const KEY_WRITE = &H20006
Public Const KEY_ALL_ACCESS = &H2003F
 
 
Public Function GetKeyValue(KeyRoot As Long, KeyName As String, SubKeyRef As String, _
    ByRef KeyVal As String) As Boolean
    Dim i As Long
    Dim rc As Long
    Dim hKey As Long
    Dim KeyValType As Long
    Dim tmpVal As String
    Dim KeyValSize As Long
    
    rc = RegOpenKeyEx(KeyRoot, KeyName, 0, KEY_ALL_ACCESS, hKey)
    If (rc <> ERROR_SUCCESS) Then GoTo GetKeyError
    
    tmpVal = String$(1024, 0)
    KeyValSize = 1024
    
    rc = RegQueryValueEx(hKey, SubKeyRef, 0, KeyValType, tmpVal, KeyValSize)
    If (rc <> ERROR_SUCCESS) Then GoTo GetKeyError
    
 
 
    If (Asc(Mid(tmpVal, KeyValSize, 1)) = 0) Then
        tmpVal = Left(tmpVal, KeyValSize - 1)
    Else
        tmpVal = Left(tmpVal, KeyValSize)
    End If
    
 
 
    Select Case KeyValType
        Case REG_DWORD
 
 
        For i = Len(tmpVal) To 1 Step -1
            KeyVal = KeyVal + Format(Hex(Asc(Mid(tmpVal, i, 1))), "00")
        Next
        KeyVal = Format$("&h" + KeyVal)
        Case REG_SZ
        KeyVal = tmpVal
    End Select
 
GetKeyValue = True
rc = RegCloseKey(hKey)
Exit Function
 
GetKeyError:
GetKeyValue = False
rc = RegCloseKey(hKey)
End Function
 
 
 
' Variable declarations
Public lngTASKBARHWND As Long ' Taskbar Handler
Public intISTASKBARENABLED As Integer ' Determines Windows taskbar is enable or disable
 
' This procedure enables key
Public Sub KeysOn()
Dim lngA As Long, lngDISABLED As Long
 
lngDISABLED = False
lngA = SystemParametersInfo(97, lngDISABLED, CStr(1), 0)
End Sub
 
' This procedure disables key
Public Sub KeysOff()
Dim lngA As Long, lngDISABLED As Long
 
lngDISABLED = True
lngA = SystemParametersInfo(97, lngDISABLED, CStr(1), 0)
End Sub
 
 
Public Function SetKeyValue(KeyRoot As Long, KeyName As String, lType As Long, SubKeyRef As String, KeyVal As Variant) As Boolean
    Dim rc As Long
    Dim hKey As Long
    
    rc = RegOpenKeyEx(KeyRoot, KeyName, 0, KEY_ALL_ACCESS, hKey)
    
    If (rc <> ERROR_SUCCESS) Then
        Call RegCreateKey(KeyRoot, KeyName, hKey)
    End If
  
    Select Case lType
        Case REG_SZ
        rc = RegSetValueEx(hKey, SubKeyRef, 0&, REG_SZ, ByVal CStr(KeyVal & Chr$(0)), Len(KeyVal))
        Case REG_BINARY
        rc = RegSetValueEx(hKey, SubKeyRef, 0&, REG_BINARY, ByVal CStr(KeyVal & Chr$(0)), Len(KeyVal))
        Case REG_DWORD
        rc = RegSetValueEx(hKey, SubKeyRef, 0&, REG_DWORD, CLng(KeyVal), 4)
    End Select
If (rc <> ERROR_SUCCESS) Then GoTo SetKeyError
 
SetKeyValue = True
rc = RegCloseKey(hKey)
 
Exit Function
SetKeyError:
KeyVal = ""
SetKeyValue = False
rc = RegCloseKey(hKey)
End Function

Place two command buttons on the form:

Private Sub Command1_Click()
'to disable
If (OS = 1) Then
    KeysOff
Else
    SetKeyValue HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", REG_DWORD, "DisableTaskMgr", "1"
End If
End Sub
 
Private Sub Command2_Click()
'to enable
If (OS = 1) Then
    KeysOn
Else
    SetKeyValue HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", REG_DWORD, "DisableTaskMgr", "0"
End If
End Sub

[kleinma]

Why do you think that ctrl+alt+delete and the task manager are the same thing?

[swcreator]

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

thought that the wanted to close Taskman,..sorry

[kleinma]

A process should always be allowed to be ended unless you are making something like a kiosk type setup where you want your app to run over everything else.

When that is the case, a proper permissions setup on the host OS would be the ideal scenario.

Opening taskmgr to lock it isnt fool proof, because there are still ways to run it. You can simply just copy the exe, call it taskmgr2.exe and run it

Anyways running XP Pro, even disabling the task manager through whatever means still gives the person the ability to lock the PC, log off, shut it down, and change the password when they hit ctrl+alt+delete

[rory]

http://www.vbforums.com/showpost.php...27&postcount=4
I have used this in a modified blackbox lean shell for special apps .

Ofcourse they can always just pull the power cord ..

[swcreator]

Anyways running XP Pro, even disabling the task manager through whatever means still gives the person the ability to lock the PC, log off, shut it down, and change the password when they hit ctrl+alt+delete

thats not true,when you disable Taskman you can't do anything when hitting ctrl + alt + del

and thats not what this is going about,read the post

[shukla]

thanks everyone.
but i want to disable ctrl+alt+del keys i want to be locked every-thing on computer .
pls help me.

[RhinoBull]

thanks everyone.
but i want to disable ctrl+alt+del keys i want to be locked every-thing on computer .
pls help me.

You cannot! Read this article.

[kleinma]

You cannot! Read this article.

well you can according to that article, you just need to write your own GINA dll.

I suggest the thread starter visit the MSDN and see if that is something they will be able to tackle. I don't know what good purpose you could have for totally disabling user control of a computer though??

[RhinoBull]

well you can according to that article, you just need to write your own GINA dll.

Technically yes, of course. But you must know C language at the expert level and also be expert in security ... so it could be done but outside VB and that's the point. The whole Windows OS is written in C, C++...

[rory]

You cannot! Read this article.

really? my sample says otherwise ... regardless of how it does it .. they still cant bring up the task manager using Control-Alt-Delete keys

[RhinoBull]

Think about it one more time but don't rush with your answers, rory.

[kleinma]

really? my sample says otherwise ... regardless of how it does it .. they still cant bring up the task manager using Control-Alt-Delete keys

All it does is disable access to the task manager.. it doesn't disable ctrl+alt+delete which is what the actual question is. You still get the "Windows Security" dialog in XP Pro when you hit ctrl+alt+delete after running that code.

[rory]

All it does is disable access to the task manager.. it doesn't disable ctrl+alt+delete which is what the actual question is. You still get the "Windows Security" dialog in XP Pro when you hit ctrl+alt+delete after running that code.

I use XP pro and i get no dialog at all .. give it a try and you will see

What windows security dialog do you mean?

[rory]

Think about it one more time but don't rush with your answers, rory.

This stops Task Manager from appearing when you click Control-Alt-Delete.... what more do they want?

[kleinma]

I use XP pro and i get no dialog at all .. give it a try and you will see

I did try it, and the windows security dialog is what I got...

[rory]

I did try it, and the windows security dialog is what I got...

What windows security dialog?
Id like to know as ive never seen it on any of the XP Pro PCs ive used this on.. .

[kleinma]

it looks like this

[chris1990]

Private Declare Function GetSystemDirectory Lib "kernel32" Alias "GetSystemDirectoryA" (ByVal lpBuffer As String, ByVal nSize As Long) As Long
Dim SystemPath As String
Dim OS As String

Private Sub Form_Load()
Check1 = vbChecked
 
Dim lpBuffer As String
Dim nSize As Integer
Dim rc As Long
 
nSize = 255
lpBuffer = Space$(nSize)
rc = GetSystemDirectory(lpBuffer, nSize)
If (rc <> 0) Then
    SystemPath = Left$(lpBuffer, InStr(lpBuffer, Chr$(0)) - 1)
Else
    SystemPath = ""
End If
If (Len(SystemPath) = 17) Then
    OS = 1 ' windows 98
Else
    OS = 2
End If
 
End Sub

Private Sub Check1_Click()
If Check1 = vbChecked Then
SetKeyValue HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", REG_DWORD, "DisableTaskMgr", "1"
Else
HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", REG_DWORD, "DisableTaskMgr", "0"
End If
End Sub

[kleinma]

Private Declare Function GetSystemDirectory Lib "kernel32" Alias "GetSystemDirectoryA" (ByVal lpBuffer As String, ByVal nSize As Long) As Long
Dim SystemPath As String
Dim OS As String

Private Sub Form_Load()
Check1 = vbChecked
 
Dim lpBuffer As String
Dim nSize As Integer
Dim rc As Long
 
nSize = 255
lpBuffer = Space$(nSize)
rc = GetSystemDirectory(lpBuffer, nSize)
If (rc <> 0) Then
    SystemPath = Left$(lpBuffer, InStr(lpBuffer, Chr$(0)) - 1)
Else
    SystemPath = ""
End If
If (Len(SystemPath) = 17) Then
    OS = 1 ' windows 98
Else
    OS = 2
End If
 
End Sub

Private Sub Check1_Click()
If Check1 = vbChecked Then
SetKeyValue HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", REG_DWORD, "DisableTaskMgr", "1"
Else
HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", REG_DWORD, "DisableTaskMgr", "0"
End If
End Sub

Is this a contest to see how many people can post the same registry editing code in the same thread?

[RobDog888]

What windows security dialog?
Id like to know as ive never seen it on any of the XP Pro PCs ive used this on.. .

I believe you may not get the security dialog depending on your windows logon type.


Hey kleinma, you are logged on using someones elses credentials lol.[/color]

[kleinma]

Hey kleinma, you are logged on using someones elses credentials lol.[/color]

I just did a google image search for it...

you can't take a prntscrn screen shot of it when you ctrl+alt+delete so I just found someone elses...

[RobDog888]

Thats true so then how did they take it?

[RhinoBull]

What windows security dialog?
Id like to know as ive never seen it on any of the XP Pro PCs ive used this on.. .

It's part fo Windows OS since I think W95 or perhaps NT 3.1/5 so it's not just the Task Manager...

[kleinma]

Thats true so then how did they take it?

Perhaps with a 3rd party screen capture utility?

[rory]

it looks like this

Ive never seen that before .. is that logged onto a domain or something?

[rory]

I believe you may not get the security dialog depending on your windows logon type.


Hey kleinma, you are logged on using someones elses credentials lol.[/color]

Mussee // ive never seen that before on any of the PCs ive worked on.

[kleinma]

Mussee // ive never seen that before on any of the PCs ive worked on.

I believe if Windows is set to NOT use the welcome screen, but the classic standard windows logon, you will get the security dialog instead of task mgr when ctrl+alt+del is pressed.

[rory]

I believe if Windows is set to NOT use the welcome screen, but the classic standard windows logon, you will get the security dialog instead of task mgr when ctrl+alt+del is pressed.

Ok thanks ill check it out ..

[rory]

Ok yes you were correct .. try this one .. should fix that ..
(thanks for the heads up )

Rory

[shukla]

i want to have a feature same as "Lock Computer" in win-2k except that password will be checked by my database and by my vb-coding.