Helping people with computers... one answer at a time.
Windows Explorer does a lot on its own, but add-ons make it even more powerful. Unfortunately, add-ons can sometimes also add problems.
Suddenly, I can't rename, move, or delete raw files (photographs). I am constantly loading photos from my camera to my computer. In order to keep track of them and make them conveniently accessible for processing and after processing, I rename them and move them to folders. Usually, I make copies during processing and then delete them. I have been doing this on this computer for a year and a half. I have never before had anything unusual happen when renaming, moving, or deleting raw files. These files are in the My Documents folder. I view the thumbnails when renaming, moving, or deleting. Suddenly, raw photo files on my desktop computer or folders containing raw files cannot be renamed, moved, or deleted. A box opens saying, The action can't be completed because the file is open in Windows Explorer. But the file is not open and no photo applications are open. ...
Actually, the file is open. In Windows Explorer.
But because this has been working for you for some time, it's also clear that something has changed.
First, we need to understand just a little bit of how Windows Explorer works, make some guesses as to what may have changed, and suggest a couple of possible approaches to fixing - or at least working around - this problem.
We think of Windows Explorer as simply a program to explore the files on our computers.
Windows Explorer supports several "views" of files. The one above is the Details listing of files. If I select instead Large Icons, the display is more like this:
That's a convenient approach to browsing your photos without needing any extra software.
You might notice that those are all .jpg files, a very common format that Windows Explorer understands natively.
Windows Explorer doesn't understand RAW image formats on its own.
To browse as you are evidently doing, something had to be added.
Much like Internet Explorer (similarly named, but a different program used for a different purpose), the functionality of Windows Explorer can be extended by adding a type of plugin or add-on called a "shell extension". (The "shell" refers to Windows primary user interface, which is indeed Windows Explorer.)
Windows Explorer comes with a lot of built-in functionality and it comes with a number of shell extensions that extend that functionality.
But it doesn't support raw formats.
Somewhere, somehow, there's a third-party, probably non-Microsoft shell extension that's been added in order for raw files to be viewable in Windows Explorer. (A quick search shows that there are many available.)
Here's my guess as to what's happened.
The software that is the shell extension has been updated. Perhaps as a side effect of installing new software, perhaps as a side effect of updating some existing software. Perhaps just as a simple update itself.
And that update has a bug.
My guess is that in order to display the icon or thumbnail of the raw formatted image, the shell extension is opening the file to read its contents and failing to close it. As a result, Windows Explorer does indeed "have the file open". And it shouldn't.
I could be wrong, but that's what it feels like.
There are a few approaches to dealing with or working around this problem.
Naturally, if you realize that the problem started when you updated or installed something, that gives you some hints as to where to look. I'd certainly investigate the support options available for whatever that software was so as to see if there have been similar reports of a problem like this and an official answer or update.
Don't use Icon view. Based on what you're doing, this is probably not helpful because you're using the Icon view to see the image in order to give it an appropriate name. But I'm guessing that if an icon isn't displayed, the file won't be left open and you'll be able to copy, move or do whatever you need to the file.
Don't use Windows Explorer. Windows Explorer is a fine general purpose file browser, but its abilities to deal with images are very basic, and kind of an afterthought, to be honest. Instead, a program like FastStone Image Viewer, which is free, operates very much like Windows Explorer, but is specifically an image browser and viewer. It supports RAW formats natively and does pretty much everything that you've described yourself as doing. Other programs, like IrfanView, Adobe Bridge, and others, can also be used to the same effect.
If you feel comfortable getting a little geeky, we can look underneath Windows Explorer's hood a little with ShexView (also ShellExView), a free little utility from NirSoft that will list the shell extensions present on your machine.
As this program allows you to disable shell extensions, I strongly suggest that you backup your system first, just in case.
On my machine, there are 254 shell extensions loaded. The vast majority are from Microsoft and are part of the core Windows installation. Many others, however, represent extensions that have been added by other programs that I have installed on my system.
The columns are all clickable, so I'd start by sorting by the "Company" column and then looking for non-Microsoft shell extensions that either might relate to software that you've recently installed or updated or that relate to some of the image or photo-related software on your machine.
At a minimum, this could point you at the software that might be responsible and direct your further investigation.