Image:

Steps:

1. First, click on the blue folder icon for the category under which you wish to create a new category.

2. Click "Add Category".
    
3. A new category labeled "New Category" will appear.
    
4. Click on "New Category".
    
5. Press F2 or slowly single-click a second time to rename the category.
    
6. Type in a new name for the category and press enter.