Helicon Photo Safe is a powerful free photo manager with a stack of useful features.
The program opens with a smartly-designed thumbnail browser, initially centred on your Pictures folder. Wide file format support (JPEG, PNG, GIF, PSD, DNG, and various manufacturer-specific RAWs) means you should be able to see everything that matters, and you can browse other folders in a click or two.
Double-clicking any image opens it in an excellent viewer. This isn't just some static full-screen display, either. You can dynamically zoom in and out just by moving your mouse cursor and spinning the mouse wheel; buttons to rate, categorise or delete the image help speed up photo management; and Back/ Next navigation buttons mean you can browse an entire folder of pictures in a few clicks.
If you spot a photo with issues then the "Quick Edit" window may be able to help. This provides capable Crop and Rotate tools, an easy way to straighten skewed images, along with adjustments for brightness, white balance, saturation and sharpness.
A useful tool for comparing photos displays your two candidate images in separate panes. This supports synchronised zoom, too: pan and zoom the first image, and the second automatically does the same, making it quick and easy to spot any differences.
There are plenty of other features on offer here. You can geotag photos with Google Maps; upload them directly to Facebook, Flickr or Picasa; perhaps burn them to CD or DVD. And you can even store personal photos in a "Safe", a secure container whose contents only become visible once you've entered the password.
And the authors claim all this happens at high speed, almost regardless of your library size, with Helicon Photo Safe able to browse "hundreds of thousands of images without any performance hiccups".