… and these days, getting something(useful) for ‘free,’ is a rarity. Not only is the Irfanview image-editing program free, but it includes features we would normally expect to pay for. Irfanview will re-size, re-name, convert and/or add watermarks to your images, amongst many other tasks, and the bonus is….it will do so as a batch process. Making changes to a folder full of images all at once, instead of individually, saves so much time!

Irfanview website

Installation instructions