FYI, I am using IIS7 with PHP version 5.2.9 on my localhost.
After a couple of googling - I figured out a simple solution to make my gallery work.
Below are the steps I've done.
1. Open IIS7
2. Scroll down to the website you are working on and then go to the gallery default folder of WP NextGen. Right click on it and select Edit Permissions...
3. The gallery properties will pop out on your screen and then you need to do the following steps:
- go to Security tab
- Click Edit, another pop up window will show (Permission for gallery)
- Select CREATOR OWNER
- Tick Full control on the permissions
- Click Apply
After completing all the steps above you may now see the images on the folder itself and your gallery will now work on your website.
Hope it works with you guys...