Going to this folder, C:\Users\Public\Documents\Stardock\WindowBlinds, it's not enough to count the folders and suggest that's how many skins you have installed. Some of them are WindowBlinds system folders. And sometimes when you delete a skin, the folder is not deleted because Windows think the fonts in that skins folder are still in use. These folders however, can be deleted manually after you have signed out and back in again.
If you look in the folder mentioned above, I suggest you look for the folder(s) of the skin(s) you can't find and see if they seem to be correctly installed (there should be quite a few files in there) and/or try to reinstall those skins.
