How do I stop Elements creating a folder called Adobe in my Documents folder

We are users of an Elements forum, not a Microsoft one. It's good to discuss also operating systems and their connections with our softwares, but it helps a lot not to introduce confusion when discussing best practices. 

There would have been less trouble if Microsoft had called 'My Pictures' and 'Documents' otherwise; they are parts of a system architecture offered to software developpers for managing their apps; they are also there to provide some help to final users to somehow manage their own personal data.

Whether you like it or not, Adobe does use those system folders 'as designed'. Those default folders also help beginners a lot, and have a number of advantages, but they are not a 'private property' and 'secret' location. 

It's an excellent thing to want one's own data neatly separated from other computer data, settings and programs. As a matter of fact, you are at home and alone if you create a folder 'My private data' anywhere else on your computer, on another partition or disk. Or even as a subfolder of  'My Pictures'! The illusion is to think in terms of folders, which is the main reason people have issues with the Organizer which is NOT based on folders even if it can manage them.

To be clear, I don't use 'My Pictures' for a number of reasons. I store my photos and catalogs elsewhere, on a personal 'My photos' master folder in another drive (internal or external). Yes, That's where I also store the catalog folder, which is otherwise stored in a hidden default location of your C drive. 

I was just curious! I did not realize that it was even on my PC until you mentioned it. Adobe Photoshop Elements needs to create and use MANY folders on your PC when you install and use the software.

I think that the answer to your question is to just uninstall Elements from your PC. If you do that, you will no longer have that pesky Adobe folder in your documents folder.