Windows 7 added a "multiple picture Slideshow" feature to the desktop background settings.
You are not able to make an animated GIF work normally, but you can break up the GIF into single frames and the slideshow feature will run it as if they were still together.
Remember to order the frame numbers with zeros when naming them (e.g.
name003 instead of
name3) to avoid the dreaded
1, 10, 11, 2, 20, 21, ordering.
Remember to uncheck the "random" box at the bottom and adjust the delay down to 10 seconds (the minimum). Obviously speed leaves much to be desired with the minimum delay between frames of 10 seconds, but at least you will get your moving background again.