Requirements
iTunes for Windows -
http://www.itunes.com/
iTunes Store Account - you can easily register for an account using your CC for free. You only need your CC for authentication. Otherwise, you can use
http://www.tunecore.com/freealbum for a free gift which will create your an iTunes Store Account
iTSfv -
http://itsfv.sourceforge.net/
Install iTunes and iTSfv
Load iTSfv
Automatic method
Browse an album in iTunes Store
Click on the first track in the album
In iTSfv, using Selected Track menu, click Export iTunes Store track Artwork
Manual method
In iTSfv, using Tools menu, click iTunes Artwork Grabber
It will do its thing and try prompting you to save the Artwork
I tried it in a few albums and seems to work well.
Enjoy,
McoreD