Rotating images should be simple process and usually it is but it's not without it's complications - there's always a loss of quality involved.
To rotate the image, most image editors decode the photo, rotate it and then re-encode it back to it's original format which is why the decrease in quality takes place. JPEG Lossless Rotator on the other hand does not recode photo therefore meaning quality is not lost. Once installed, JPEG Lossless Rotator will create thumbnails of images in your designated folder including sub folders if need be.
To rotate, select a photo thumbnail and select the appropriate rotation angle you want to use, using the tools at the top of the interface. Apart from that, there are only a few other options such as "Recent Folder" which opens the folder that was opened before the program window was closed last time, "Favorites" which adds and keeps the 10 last chosen shortcuts to folders. There's also an "Automatic" feature which automatically rotates slanted images to make them straight.
It's hard to tell with the naked eye whether JPEG Lossless Rotator really rotates without a loss of quality but if you can't afford to take chances, it's better than using a standard image rotation tool.