These aren’t the correct instructions for the latest version of widgetkit:
With the Pure & Simple theme, you get a custom theme for the slideshow to match what you seen on the live demo website. You can find this style in the the “Puresimple-package” folder, then in that you will find a folder named “widgetkit”. Inside that is a folder named “slideshow”, and within it is a folder named “pureandsimple”.
Using your FTP program, upload the “pureandsimple” folder into the “styles” folder in the location given below: