photo in use message prevents moving images

> When moving image folders from one drive or location to
> another, I may or may not be able to move it. After
> viewing an image, or working with it, I have a need to
> move the entire folder to another computer. When I do so,
> the move command moves all of the files to the new
> location (into a folder of the same name) but refuses to
> take the original folder there also. I get a popup dialog
> box that tells me that the images files are in use and it
> cannot be moved. It ends up being a hybrid move.
>
> I end up with an empty folder in the original location
> and the only way I can eliminate the folder is to reboot
> my computer.
>
> How can this be stopped?