There is an issue in the current version of Windowblinds when you try to delete a skin. If you open Windowblinds and delete a skin, it does not remove the skins folder if there are fonts in it. If you try to delete the folder manually it will not let you saying that the folder is in use.

If you reboot the computer and do not open Windowblinds, the folder can be deleted. But if you open Windowblinds, and don't even do anything in and and close it, and then try to delete same said folder, it will not let you again.

Irritating, please fix, thanks. 

One other thing too, if you delete a skin manually in the Windowblinds folder, and then open Windowblinds afterwards, the names for the skins you've removed still appear without thumbnails. You have to do a rebuild list to get them to go away. Any way of setting Windowblinds to automatically do a rebuild list when you open it, or when you add a new skin? Sure would be nice.