OK, I figured it out. I was confused about how to install it. Here's what I did to get it working, in case someone else is having a similar problem:
1.) Download the zip version of TinyWebGallery:
http://www.tinywebgallery.com/download. ... ery=latest
2.) Unzip this file to your desktop and open the folder twg178 and then the folder twg178 in there. (Folder name may change depending on the current version available.) Highlight and copy all the files and folders in there (admin, buttons, cache, counter, dtree, examples, etc., etc.) and paste them into a folder you create in the C:\xampp\htdocs folder called tinywebgallery (you could name it anything you want. I just called it tinywebgallery cuz astrosmashjamboreebeewax wouldn't have made as much sense).
3.) Then, if you have xampp services on, punch localhost/tinywebgallery into your browser, and you should be good. Put a /admin at the end of that address and boom, you're on the admin page! Or /info.php and you're on the info page.
Here's a nice link discussing setting up xampp for use with streaming audio:
http://www.maximumpc.com/article/howtos ... y_computer but useful for this purpose too.
Thanks for you help, and good luck to all!
-snakelips