How you save the wallpaper will depend on the browser that you are using to surf the web. If you do not know how to save wallpaper to your desktop, please find the browser you are using below and follow the steps to save your wallpaper.
Internet Explorer
If you are using Internet Explorer, find the wallpaper that you want to use for your desktop. Right click on the wallpaper and wait for the menu to open. In the menu, select the "Set as Background" link in the menu. Give it a second and the wallpaper will be set as your background. You can then minimize everything and see your new wallpaper.
Firefox
If you are using the Firefox browser, follow these steps. Find the wallpaper you want to use. Right click on the wallpaper and wait for the menu to pop up. In the menu, click the "Set as Desktop Background" option. Give it a second to change your desktop and then minimize everything to see your new wallpaper.
Chrome
If you are using Chrome, you will have to take a couple of extra steps to get a new wallpaper. You will first need to locate the wallpaper you want to use. Then right click on the wallpaper and click the "Save Image As" option. A box will open and you will need to save the wallpaper to your desktop. Then go to the desktop and right click on the wallpaper you just saved. When the menu opens, click the "Set As Desktop Background" option. That will apply the new wallpaper to your desktop.