Binaryworld - EnumRegistryKeys - Retrieve all the subkeys of a Registry key ... [ VB -> Windows ]

Private 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
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As _
  Long
Private Declare Function RegEnumKey Lib "advapi32.dll" Alias "RegEnumKeyA" _
  (ByVal hKey As Long, ByVal dwIndex As Long, ByVal lpName As String, _
  ByVal cbName As Long) As Long

Const KEY_READ = &H20019 ' ((READ_CONTROL Or KEY_QUERY_VALUE Or
             ' KEY_ENUMERATE_SUB_KEYS Or KEY_NOTIFY) And (Not
             ' SYNCHRONIZE))

' Enumerate registry keys under a given key
'
' returns a collection of strings

Function EnumRegistryKeys(ByVal hKey As Long, ByVal KeyName As String) As _
  Collection
  Dim handle As Long
  Dim length As Long
  Dim index As Long
  Dim subkeyName As String

  ' initialize the result collection
  Set EnumRegistryKeys = New Collection

  ' Open the key, exit if not found
  If Len(KeyName) Then
    If RegOpenKeyEx(hKey, KeyName, 0, KEY_READ, handle) Then Exit Function
    ' in all case the subsequent functions use hKey
    hKey = handle
  End If

  Do
    ' this is the max length for a key name
    length = 260
    subkeyName = Space$(length)
    ' get the N-th key, exit the loop if not found
    If RegEnumKey(hKey, index, subkeyName, length) Then Exit Do

    ' add to the result collection
    subkeyName = Left$(subkeyName, InStr(subkeyName, vbNullChar) - 1)
    EnumRegistryKeys.Add subkeyName, subkeyName
    ' prepare to query for next key
    index = index + 1
  Loop

  ' Close the key, if it was actually opened
  If handle Then RegCloseKey handle

End Function