If you want to delete a folder you can right click it and a popup menu will be displayed. Select the Delete Folder option and the folder will be deleted.

Another way to delete a folder is to click on the desired folder and then to go File Menu, select the Folder option and then select the Delete Folder option.

NOTE: When you delete a folder all the items in that folder will be deleted. Also, all the subfolders and their items will be deleted.