Theme Changer was written to change .CAB themes with system screens and can show a summary of the theme. The new version adds the ability to browse for backgrounds, schedule to automatically change the background image.
Theme Changer was written to change .CAB themes with system screens (that the MS settings program can’t) and give a summary on the theme. This version adds new features to allow browsing backgrounds and automatic changing of backgrounds. And its free!
Also available is a theme pack.