Can’t open PNG files or convert them…? Use FastStone!
An image browser, converter and editor that supports all major graphic formats including BMP, JPEG, JPEG 2000, GIF, PNG, PCX, TIFF, WMF, ICO and TGA. It has a nice array of features such as image viewing, management, comparison, red-eye removal, emailing, resizing, cropping, color adjustments, musical slideshow and much more.
*FastStone Image Viewer and FastStone Photo Resizer are provided as freeware for personal and educational use. In these cases, you are granted the right to use these programs free of charge. However, for commercial use, license is required.