I have tried resizing a picture for a friend but for some reason I need to set to 1600 by 2400 pixels but even if I do have it set by Paint.net it says its the wrong size when she tries to upload it.
The FastStone products are excellent. I use the FastStone Image Viewer. It includes the viewer which makes it very easy to resize images.
FastStone Resizer can do many files at a time. So, to me, that is an advantage over the FS Image viewer. Both are superb products.
There's always Gimp. https://en.wikipedia.org/wiki/GIMP http://www.gimp.org/ Then just go Image > Scale Image.
Yes, batch resizing is a great feature when you have multiple pics and you want to resize them all at the same time (to the same size). I like the image viewer because I often need to resize individual pics to nonstandard sizes. Why not install both of them?
It's worth taking a look at the free version of Zoner too, it all depends on your needs: http://free.zoner.com/
...or the same percentage, or different or the same destination directory... Both is is the way to go for max flexibility.
I think Paint.NET is getting a little quirky/buggy these days. There are some decent freeware programs out there, most have already been mentioned. Two I like are Pinta 1.6 and PhotoFiltre 7. http://pinta-project.com/releases http://www.photofiltre.com/
If you're looking for a real simple one, you can try this: http://www.enderminh.com/minh/photoresizer.aspx
