Not Showing up.

I have been using Icon packer for years now but i havent used it in ages. I have found what i like and i have downloaded it, But its not showing up in the display window. Its in the program files, but not in the program window to apply the icons. Can anyone help me here, Is there a link to tell me step by step on the how to's. Or just tell me what i have done wrong. Or a trouble shooting site.
Thank you, Peachy!!