Making thumbnails with Picasa
Run Picasa (download from Google) Size it, then [Alt] [Prs Sc]
Copy the entire Picasa screenshot into Paint then grab the one you want...
Do a File/New in Paint, then paste in your thumbnail
Now save that one image as a JPG and you have your thumbnail
Picasa is a program you can download from Google -- no cost. If you store images on your hard drive, it's an awesome tool even if you don't want to make thumbnails.