Private Declare Function OpenThemeData Lib "uxtheme.dll" (ByVal hwnd As Long, _
 ByVal pszClassList As Long) As Long
Private Declare Function CloseThemeData Lib "uxtheme.dll" (ByVal hTheme As Long) As Long
Public Function ThemesEnabled(hwnd As Long) As Boolean
  Dim hTheme As Long
  
  hTheme = OpenThemeData(hwnd, StrPtr("Window"))
  CloseThemeData hTheme
  ThemesEnabled = hTheme <> 0
End Function

  Private Declare Function OpenThemeData Lib "uxtheme.dll" (ByVal hwnd As IntPtr, _
   ByVal pszClassList As String) As IntPtr
  Private Declare Function CloseThemeData Lib "uxtheme.dll" _
   (ByVal hTheme As Integer) As Integer

  Public Function ThemesEnabled(ByVal hwnd As IntPtr) As Boolean
    Dim hTheme As IntPtr = OpenThemeData(hwnd, "Window")
     CloseThemeData(hTheme)
    Return hTheme <> 0
  End Function
...
   MsgBox(ThemesEnabled(Me.Handle))

  Private Declare Function IsThemeActive Lib "uxtheme.dll" () As Boolean
  Private Declare Function IsAppThemed Lib "uxtheme.dll" () As Boolean

  Public Function App_ThemesEnabled() As Boolean
    Return IsThemeActive AndAlso IsAppThemed
  End Function

      SetWindowTheme hwndLv, StrPtr("explorer"), 0 'VB6