My 1 year old Windows 10 desktop computer has a 256GB solid state C-drive, and it was getting pretty full, so I started to transfer lots of stuff to my internal F-drive (3TB) to get it back to a comfortable fill level.

I moved lots of folders and files (like the contents of the "Documents" folder, for example) that don't affect the Windows operating system or the running of programs, but soon discovered that there are other folders which I don't quite know how they affect things were quite large.

Now to the point: In the "users/Stephen/App Data/Local/" folder resides the "Responsive Site Designer/cache" folder, and it has a whopping 82GB of content... a significant part of the 256GB solid state drive capacity. There are 71 numbered folders in it, with dates going back to the beginning experiments with RSD.

I want to delete most of the folders, and only retain what is necessary to continue working with the current versions of my RSD websites... perhaps 90% can go (or maybe all of it???).

What can I do?

Seems like I reported this issue before. It may have been RLM that was doing this same thing.

What's the safe way to proceed - some of the cache for older websites id buried somewhere in the folder list, and I don't know if I really need to keep any of it at all anyway.

I don't think any of it's needed. It for rendering of your site as your working on it.