Microsoft offers personalization gallery for to make Windows better and refreshing for you. Through this Microsoft offers occasional free downloads in the form of Windows themes, Desktop backgrounds (wallpapers), Windows gadgets.
Some of the themes released under personalization gallery have stunning imagery, so I do you extract images from these theme packs to use it elsewhere.
The process is pretty simple, all you need is a Win Zip program, I use 7-Zip, extract the contents of the theme file to a folder using 7-zip or other win zip program and you will find the images associated with that theme.
If you have already installed the theme and want to extract those images, then go to the below given location in your machine, you will find the images.
In Windows 7 (Vista path also should look similar)
C:\Users\(your user name)\AppData\Local\Microsoft\Windows\Themes
If you havenâ€
Download Windows 7 Themes