Como gravar dados no registro do windows xp

Estou usando o seguinte código.

Em um módulo:

Option Explicit

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 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

Global Const ERROR_SUCCESS = 0&
Global Const ERROR_BADDB = 1009&
Global Const ERROR_BADKEY = 1010&
Global Const ERROR_CANTOPEN = 1011&
Global Const ERROR_CANTREAD = 1012&
Global Const ERROR_CANTWRITE = 1013&
Global Const ERROR_REGISTRY_RECOVERED = 1014&
Global Const ERROR_REGISTRY_CORRUPT = 1015&
Global Const ERROR_REGISTRY_IO_FAILED = 1016&
Global Const HKEY_CLASSES_ROOT = &H80000000
Global Const HKEY_CURRENT_USER = &H80000001
Global Const HKEY_LOCAL_MACHINE = &H80000002
Global Const REG_SZ = 1

Global Const REGKEY = "SOFTWAREMaterial de Construção do Branco"

Global RETVALUE As Long
Global RESULT As Long
Global KEYID As Long
Global KEYVALUE As String
Global SUBKEY As String
Global BUFSIZE As Long

No form

RETVALUE = RegCreateKey(HKEY_LOCAL_MACHINE, REGKEY + "Menu", KEYID)
  For CONTADOR(1) = 1 To 4
    BUFSIZE = 0
    SUBKEY = CONTADOR(1)
    RETVALUE = RegQueryValueEx(KEYID, SUBKEY, 0&, REG_SZ, 0&, BUFSIZE)
    If BUFSIZE < 2 Then
      KEYVALUE = ""
      RETVALUE = RegSetValueEx(KEYID, SUBKEY, 0&, REG_SZ, ByVal KEYVALUE, Len(KEYVALUE) + 1)
    Else
      KEYVALUE = String(BUFSIZE + 1, " ")
      RETVALUE = RegQueryValueEx(KEYID, SUBKEY, 0&, REG_SZ, ByVal KEYVALUE, BUFSIZE)
      KEYVALUE = Trim(Left$(KEYVALUE, BUFSIZE - 1))
      CONTADOR(2) = 1
      While CONTADOR(2) <= 3
        Select Case CONTADOR(2)
          Case 1: Set FORMULÁRIO = Estoque
          Case 2: Set FORMULÁRIO = ProdutosDiferenciados
          Case 3: Set FORMULÁRIO = Vendas
        End Select
        FORMULÁRIO.ArquivoMenu(CONTADOR(1)).Caption = CONTADOR(1) & ". " & KEYVALUE
        FORMULÁRIO.ArquivoMenu(CONTADOR(1)).Visible = True
        FORMULÁRIO.separador2.Visible = True
        CONTADOR(2) = CONTADOR(2) + 1
      Wend
    End If
  Next
  Set FORMULÁRIO = Nothing

O que eu acho estranho é que no 95, 98 e no Me funciona normalmente, mas no xp essa dll não funciona mais... e eu já verifiquei q no xp essa dll existe.
Será q alguém pode me ajudar?