>I've also discovered that, despite being logged in as administrator and despite the fact that I took out the requirement to open the file exclusively, the user still can't open the file. It is still throwing error 3 - file is in use. But I had him immediately go to Windows Explorer and he was able to rename the file with no problem. Arrrggghhhh . . .

Russell, is it possible that this file has an extension that is not visible, but that it was inadvertedly changed somehow?

PowerDesk (file and directory manager, among other things) allows you to completely and truly rename a file. Surely there are other tools that do the same thing, but I don't think the default is permit file name changes like that. Good luck!