This declaration is better:

        Private Declare Unicode Function WritePrivateProfileString Lib "kernel32" Alias "WritePrivateProfileStringW" _
         (ByVal lpApplicationName As String, ByVal lpKeyName As String, ByVal lpString As String, _
         ByVal lpFileName As String) As Int32

However, when I execute the write, I obtain a result of 0. This doesn't tell me that much. Is there a way to obtain more information when the result is 0?