SAVE:
Right Mouse on image below.
Click Save Picture As.
Give it a Name, and chose a Folder to save it in.

INSTALL:
Go to your Desktop and Right Mouse on Background.
Click Properties. Click Desktop Tab at top.
Click Browse Button and find the Folder you saved to.
Click the File Name you called it and Click Open.
Open the Position Box and Click Stretch to Fill Screen.
Click OK.