Const ERROR_NO_MORE_ITEMS = 259&
Const HKEY_CURRENT_CONFIG = &H80000005
Const HKEY_LOCAL_MACHINE = &H80000002
Const HKEY_CURRENT_USER = &H80000001
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As _
  Long
Private Declare Function RegOpenKey Lib "advapi32.dll" Alias "RegOpenKeyA" ( _
ByVal hKey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
Private Declare Function RegEnumKeyEx Lib "advapi32.dll" Alias "RegEnumKeyExA" ( _
ByVal hKey As Long, ByVal dwIndex As Long, ByVal lpName As String, lpcbName As _
Long, ByVal lpReserved As Long, ByVal lpClass As String, lpcbClass As Long, _
lpftLastWriteTime As Any) As Long
Private Declare Function RegDeleteKey Lib "advapi32.dll" Alias "RegDeleteKeyA" ( _
ByVal hKey As Long, ByVal lpSubKey As String) As Long
 
Private Function delregkeytree(mainkey As Long, initkey As String) As Boolean
  Dim notpossible As Boolean
  Dim hKey As Long
  Dim Cnt As Long
  Dim sName As String
  Dim Ret As Long
  Dim initlen As Long
  Const BUFFER_SIZE As Long = 255
  Ret = BUFFER_SIZE
  initlen = Len(Left(initkey, InStrRev(initkey, "\") - 1))
  If RegOpenKey(mainkey, initkey, hKey) <> 0 Then
    RegCloseKey hKey
    delregkeytree = False
    Exit Function
  End If
  RegCloseKey hKey
  sName = Space(BUFFER_SIZE)
  Do
    RegOpenKey mainkey, initkey, hKey
    While RegEnumKeyEx(hKey, Cnt, sName, Ret, ByVal 0&, vbNullString, ByVal 0&, _
      ByVal 0&) <> ERROR_NO_MORE_ITEMS
        success = RegDeleteKey(hKey, Left(sName, Ret))
        If success <> 0 Then
          If notpossible = False Then
            initkey = initkey & "\" & Left(sName, Ret)
          End If
          Cnt = Cnt + 1
          notpossible = True
        End If
        sName = Space(BUFFER_SIZE)
        Ret = BUFFER_SIZE
    Wend
    If notpossible = False Then
      lastkey = Right(initkey, Len(initkey) - InStrRev(initkey, "\"))
      initkey = Left(initkey, InStrRev(initkey, "\") - 1)
      RegOpenKey mainkey, initkey, hKey
      success = RegDeleteKey(hKey, lastkey)
    End If
    Cnt = 0
    RegCloseKey hKey
    notpossible = False
  Loop Until Len(initkey) = initlen
  delregkeytree = True
End Function
 
Private Sub Command1_Click()
  Debug.Print delregkeytree(HKEY_CURRENT_USER, _
    "SOFTWAREMicrosoftWindowsCurrentVersionRun")
End Sub