This is a quick, easy, free way to have an animated desktop background.(Using pictures, not videos.) (:P
Step 1: Get The Software
Don't worry. This isn't a hard piece of software to use, find, and isn't pricy.
The link is HERE whitsoftdev.com/files/unfreez.zip
Step 2: Get Your Pictures
You can either take pictures and make them into an animation, or just use internet pictures. Make them into a folder. (It's easier that way.) P.S. Don't have 1 trillion pictures, because it will create epic noobish lag on your computer, and you have to do something soon that will affect how long this "operation" will take.
Here are the pics I used.
Step 3: Converting Your Pictures To .GIF Files
IF your pictures are not .GIF files, we will have to convert them. This is why you do not want to have too many pictures.(IT TAKES FOREVER.) Open up Microsoft Paint. (If you do not have it, I think there are some downloads on Download.com) Paste one of the pictures in it by copying the picture, (right click, copy.) and then in MS Paint, click on the icon as shown on in the picture. Just click on the top one, not the bottom one.( You'll know what I mean.) Now paste the picture. (Right click, paste.) When saving it, under the area for you to title it, there will be a drop bar. Click GIF and now your picture is in .GIF format, so it will be compatible with the software you downloaded earlier. Do this for all of your pictures.
Step 4: Here We Go!
Open up the software you downloaded earlier. Drag each picture into the area where it says "Frames. Drop .GIF files here" You may need to put the same pictures in multiple times consecutively, so they will last longer on the screen,(four times is a good 2 secs.) because the frame delay option doesn't work. Now click "Make animated .GIF" in the bottom left corner.