Disable Ctrl-Alt-Delete in .net

[damicatz]

I am writing a program for my school that restricts access to various areas. This has been asked before for regular VB but I would like to know if it's possible to disable Ctrl-Alt-Delete for both Windows 9x and NT/2000. I've seen various samples of code for disabling it in 9x and NT/2000 for regular Visual Basic but I wouldn't know how to get that to work in .net.

Is it possible to do this? If not what's a good way to prevent people from closing my program down using the task manager?

[hellswraith]

Most of the ways to disable the CTRL-ALT-DELETE is done through the API in VB6 if I remember. You can still use those API calls in .Net, you will just have to change a few things here and there.

[MrPolite]

but there is no way to disable that in windows nt/xp/2k, that is, as far as I know. I have a code in vb6 which disables the task manager though, you can easily write it in .NET, because the code is just changing a simple registery value: (dunno who gave me the code).

'**************************************
'Windows API/Global Declarations for i
'     sable Ctrl-Alt-Del in NT,2000,XP
'**************************************
Public Const HKEY_CLASSES_ROOT = &H80000000
Public Const HKEY_CURRENT_USER = &H80000001
Public Const HKEY_LOCAL_MACHINE = &H80000002
Public Const HKEY_USERS = &H80000003
Public Const HKEY_PERFORMANCE_DATA = &H80000004
Public Const ERROR_SUCCESS = 0&
 
 
Declare Function RegCloseKey Lib "advapi32.dll" (ByVal Hkey As Long) As Long
 
 
Declare Function RegCreateKey Lib "advapi32.dll" Alias "RegCreateKeyA" (ByVal Hkey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
 
 
Declare Function RegDeleteKey Lib "advapi32.dll" Alias "RegDeleteKeyA" (ByVal Hkey As Long, ByVal lpSubKey As String) As Long
 
 
Declare Function RegDeleteValue Lib "advapi32.dll" Alias "RegDeleteValueA" (ByVal Hkey As Long, ByVal lpValueName As String) As Long
 
 
Declare Function RegOpenKey Lib "advapi32.dll" Alias "RegOpenKeyA" (ByVal Hkey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
 
 
Declare Function RegQueryValueEx Lib "advapi32.dll" Alias "RegQueryValueExA" (ByVal Hkey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, lpType As Long, lpData As Any, lpcbData As Long) As Long
 
 
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 REG_SZ = 1 ' Unicode nul terminated String
    Public Const REG_DWORD = 4 ' 32-bit number
 
 
Public Sub savekey(Hkey As Long, strPath As String)
    Dim keyhand&
    r = RegCreateKey(Hkey, strPath, keyhand&)
    r = RegCloseKey(keyhand&)
End Sub
 
 
Public Function getstring(Hkey As Long, strPath As String, strValue As String)
    'EXAMPLE:
    '
    'text1.text = getstring(HKEY_CURRENT_USE
    '
    ' R, "Software\VBW\Registry", "String")
    '
    Dim keyhand As Long
    Dim datatype As Long
    Dim lResult As Long
    Dim strBuf As String
    Dim lDataBufSize As Long
    Dim intZeroPos As Integer
    r = RegOpenKey(Hkey, strPath, keyhand)
    lResult = RegQueryValueEx(keyhand, strValue, 0&, lValueType, ByVal 0&, lDataBufSize)
 
 
    If lValueType = REG_SZ Then
        strBuf = String(lDataBufSize, " ")
        lResult = RegQueryValueEx(keyhand, strValue, 0&, 0&, ByVal strBuf, lDataBufSize)
 
 
        If lResult = ERROR_SUCCESS Then
            intZeroPos = InStr(strBuf, Chr$(0))
 
 
            If intZeroPos > 0 Then
                getstring = Left$(strBuf, intZeroPos - 1)
            Else
                getstring = strBuf
            End If
        End If
    End If
End Function
 
 
Public Sub savestring(Hkey As Long, strPath As String, strValue As String, strData As String)
    'EXAMPLE:
    '
    'Call savestring(HKEY_CURRENT_USER, "Sof
    '
    ' tware\VBW\Registry", "String", text1.t
    '     ex
    ' t)
    '
    Dim keyhand As Long
    Dim r As Long
    r = RegCreateKey(Hkey, strPath, keyhand)
    r = RegSetValueEx(keyhand, strValue, 0, REG_SZ, ByVal strData, Len(strData))
    r = RegCloseKey(keyhand)
End Sub
 
 
Function getdword(ByVal Hkey As Long, ByVal strPath As String, ByVal strValueName As String) As Long
    'EXAMPLE:
    '
    'text1.text = getdword(HKEY_CURRENT_USER
    '
    ' , "Software\VBW\Registry", "Dword")
    '
    Dim lResult As Long
    Dim lValueType As Long
    Dim lBuf As Long
    Dim lDataBufSize As Long
    Dim r As Long
    Dim keyhand As Long
    r = RegOpenKey(Hkey, strPath, keyhand)
    ' Get length/data type
    lDataBufSize = 4
    lResult = RegQueryValueEx(keyhand, strValueName, 0&, lValueType, lBuf, lDataBufSize)
 
 
    If lResult = ERROR_SUCCESS Then
 
 
        If lValueType = REG_DWORD Then
            getdword = lBuf
        End If
        'Else
        'Call errlog("GetDWORD-" & strPath, Fals
        '
        ' e)
    End If
    r = RegCloseKey(keyhand)
End Function
 
 
Function SaveDword(ByVal Hkey As Long, ByVal strPath As String, ByVal strValueName As String, ByVal lData As Long)
    'EXAMPLE"
    '
    'Call SaveDword(HKEY_CURRENT_USER, "Soft
    '     ware\VBW\Registry", "Dword", text1.text)
    '
    '
    '
    Dim lResult As Long
    Dim keyhand As Long
    Dim r As Long
    r = RegCreateKey(Hkey, strPath, keyhand)
    lResult = RegSetValueEx(keyhand, strValueName, 0&, REG_DWORD, lData, 4)
    'If lResult <> error_success Then
    ' Call errlog("SetDWORD", False)
    r = RegCloseKey(keyhand)
End Function
 
 
Public Function DeleteKey(ByVal Hkey As Long, ByVal strKey As String)
    'EXAMPLE:
    '
    'Call DeleteKey(HKEY_CURRENT_USER, "Soft
    '
    ' ware\VBW")
    '
    Dim r As Long
    r = RegDeleteKey(Hkey, strKey)
End Function
 
 
Public Function DeleteValue(ByVal Hkey As Long, ByVal strPath As String, ByVal strValue As String)
    'EXAMPLE:
    '
    'Call DeleteValue(HKEY_CURRENT_USER, "So
    '
    ' ftware\VBW\Registry", "Dword")
    '
    Dim keyhand As Long
    r = RegOpenKey(Hkey, strPath, keyhand)
    r = RegDeleteValue(keyhand, strValue)
    r = RegCloseKey(keyhand)
End Function
 
 
 
Public Sub TaskManagerEnabled(ByVal isEnabled As Boolean)
    If Not isEnabled Then
        Call SaveDword(HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", "DisableTaskMgr", "1")
    Else
        Call SaveDword(HKEY_CURRENT_USER, "Software\Microsoft\Windows\CurrentVersion\Policies\System", "DisableTaskMgr", "0")
    End If
End Sub

dont be scared by the length of it, you can probably do that in a few lines in .NET. It's just changing a reg value