There is no default share named "Books". If you have a folder in D:\Shares named Books, you (or someone else) created it.
As for cleaning it up, you can try this:
- Log in to your server using Remote Desktop or directly connected keyboard, video, and mouse. Note: this is unsupported and (per the warning that appears when log in this way) potentially hazardous.
- Assign ownership of the folder and it's contents to the Administrators group.
- Reboot your server.
- Log back in using Remote Desktop etc. and see if you can delete the folder.
I don't guarantee that will work. If it doesn't, there is nothing that I can think of short of a new installation (which will format all connected drives) that is going to remove that folder for you.
I'm not on the WHS team, I just post a lot. :)