To the best of my knowledge there is no way to do what you are wanting to do. The windows.old folder is the archive where it stores the windows, program files, and users folders. The program files folder will not work because it has been moved and any registry entries that have been made will have to get changed. So no i do not think it is possible. what I suggest is to dual-boot both VISTA and Windows 7 that way if you need to run an application you can always go back to VISTA