Auto change your windows 7 wallpaper

It would be nice if our window 7 wallpaper changes automatically without manual tweaking .You can do this without installing any third party app.Tweak your windows 7 settings to make it happen.Follow these steps
Click on start button type in background  in the search box Now u will  be greeted with choose your desktop background window by default the picture location will be  windows photo viewer change it to
windows desktop backgrounds .Now change the time interval to 1 minute or 1 day by checking shuffle radio button.