Go to your desktop and click on the right mouse button.

Click on "Properties"

Choose "Settings"

On the right you will see a field called "display area" which tells you the screen size of your computer.

Save the .jpg file on your c: drive.

Go to the folder where you have saved the .jpg file

Go to your desktop, click on the right mouse button and click on "Properties".

Choose "Background"

On the right side you will find a menu called "Wallpaper". Click on "browse" and locate the downloaded wallpapers. Click on the .bmp folder. You should now be able to see the files on the left side of the menu. Click on the one you would like to choose.

Confirm twice through clicking on "OK".

Done!