JPEG ReSizer is a program that will let you batch resize several JPEG/JPG files at once.
This program does not have an installer. After decompressing the archive you will get through the provided download link, you will just need to run the resizer.exe file.
The program will guide you through the steps needed to complete the resizing process. You can choose any number of JPG files, no matter what its size or resolution. You can tell the program to resize the images changing their resolution, or not. Then, you will need to specify the desired width and height you wish to apply, or the percentage in which you want the program to resize the images. You can also choose to alter the color in the target image, by changing the red, green and blue levels. Then, you can define where do you want the resulting files to be saved, and if you want to keep their original names, or build a new one applying prefixes, numbers and suffixes. You can also choose to change the JPG compression percentage and the resampling method.
Once everything is set up, you can tell the program to proceed, and your images will be saved according to your directions.