An example:

In the folder "My Documents," there is a subfolder on "My Garden," in which there is a Word Document on "Deer Resistant Plants." I wanted to change this to a different subfolder. Clicked on it, and while holding click down, moved folder to the subfolder I preferred. It moves, but when it is over the preferred subfolder, even though both are highlighted together, it just won't go. I get the barrier sign mentioned in my original post.

In other examples, I want to move within the subfolder, or perhaps a sub-subfolder. Same response. Any comments would be appreciated.