Why doesn't my desktop change when I set a picture as my back round?

I have a laptop that has Windows 7 and whenever I right click on a picture to set it as my desktop backround, the backround doesn't change at all. Is there something I have to download onto my compute to change my backround?Why doesn't my desktop change when I set a picture as my back round?I don't knowWhy doesn't my desktop change when I set a picture as my back round?A box should come up after you right click set as my desktop backgroundWhy doesn't my desktop change when I set a picture as my back round?If you right-click a picture to set it as your background, it won't change because only one picture was selected. You have to create a %26quot;theme%26quot; from the personalization window by selecting all the pictures you want. To do this, first make sure all the pictures you want are saved in the same folder. Then right-click your desktop and choose personalization. At the bottom there is a link that says desktop background. Browse to the folder you need, then select which of those images you'd like. If you'd like to change themes but come back to the one you created later, you can right-click and save it.Why doesn't my desktop change when I set a picture as my back round?Another window should come up where you would select set as desktop background click that