One of the things missing from Windows 7 Starter is the ability to change desktop wallpaper. I’m not sure why Microsoft chose to leave this feature out, but many users (including myself) find the lack of it annoying.
I have done some research, and found this useful app – Starter Background Changer. It adds “Personalise” option to desktop’s right-click menu, which allows you to change the wallpaper. You can also change settings for colour, sounds and screensaver.
You can download the application from http://renaudgerson.fr/StarterBackgroundChanger/en/
Note: Installer is in French, but is straight forward to follow. The app itself is in English.