There are presently no folders in my Design Library (in the task pane). Sometimes they're there. Sometimes not. I've confirmed my File Locations in Settings is pointing to C:\ProgramData\SOLIDWORKS\SOLIDWORKS 2020\design library.
When they ARE there, the subfolders are the following, but there is no fastener or unistrut database in there (nor in the subfolders). I configured my Toolbox successfully (I think -- basically I just unchecked most of the folders for various standards and left English and Metric plus a couple of others).
Annotations
Assemblies
Features
Forming Tools
Motion
Parts
Routing
Smart components
Using Student Edition. Windows 10 on a modern PC. Screenshot below. Thanks!