In a 32-bit program, how can I get the Open/Save File Dialogs to show the files in the System32 folder of a 64-bit system?
(Wow64DisableWow64FsRedirection doesn't work, because for some reason it doesn't work for the dialog, I'm guessing because it's on a different thread. And of course using SysNative doesn't work because the user isn't aware of what's going on internally; he just wants to see the "actual" files on the computer.)
Here's another way to ask the question:
Does any 32-bit program browse a 64-bit System32 folder from the open file dialog?
I believe that this is simply not possible.
Even if you could get the dialog to show the files, what would their names be when they were returned to your 32 bit process? Sysnative is a bit of a hack and in any case not available on XP 64. This is just a consequence of overloading the system32 name.
Another thought experiment. If it were to be possible, you'd need the thread that does the enumeration to disable redirection. Since that thread is out of your control then there would have to be a published option to disable it. There isn't. It would be no good allowing you to disable redirection from the outside because that would result in DLL load failures when the 32 bit process tried to load shell extensions - you can't disable redirection if you are going to load DLLs because you'll get the wrong ones
I imagine that you are expected to write a 64 bit program if you want to get around this limitation.