With the new release of Windows 7 on October 22, Microsoft also introduced many new Windows 7 themes. There are two main categories: Featured themes and International Themes. Some have made their appearance before, but many are new.
Once you select the theme, you can save it locally or install it. After a few seconds it will automatically appear on your personalized theme collection, and it will appear on your desktop. The default time setting is 30 minutes.