This could be useful, but only if you have some
experience with HTML, CSS and script:

http://www.jsware.net/jsware/scrfiles.php5#picview

There are screenshots at the link. I made my own
thumbnail viewer, as an HTA. (An IE window powered
by script.) As you can see from the screenshots, one
chooses a folder, then the images are loaded and
displayed by IE's rendering, which is quite good.
Each image can be enlarged by clicking on it. Click
on the enlarged image to close it. I find the utility handy
for looking through a lot of stock for images needed.
The entire thing can be customized, because it's actually
just script in a webpage. File name font, thumbnail size....
All of that is easy to change, but that's where the
HTML/CSS/VBS experience comes in.