After installing Easy Thumbnails, click on the icon from your desktop and the following screen appears. The program is actually very straightforward to use.

For my test, I selected four photos from my England trip, and placed them in a directory called 'photos' (naturally)! I then used the middle window of Easy Thumbnails to locate that directory.

Then it was a simple matter of clicking on the 'Make All' button. Once that was done, I exited the program, and check the list of files, and here is what I found: