I just tried this with the Documents library. Using Details view and withInclude subfolders... selected at Tools > Folder Options > Search, in the search box type
* type:(NOT folder)
This should result in a listing ofall files inDocuments. Then press Ctrl-A to select All to cut or copy to where you want them. I would copy to a new empty folder underMy Documents before deleting anything. If you have theType column visible, you may see some types of file - shortcuts, for example - that you're not particularly interested in cluttering up your new streamlined folder with. When you're quite sure this is what you want to do, you could delete everything inMy Documents except the new folder, then move its contents one level up.
Noel