When editing an image for a PC, open the image in Windows Live Photo Gallery, which should be the default. Then, click “Edit” from the top left.
Within the editor, select “Properties,” and then “Resize Image” from the dropdown.
Under the, “Select a Size” dropdown select, "Custom." Then, insert the pixel height, in this case, 70. Once you’ve inserted the height click, “Resize and Save.”
Your resized image will be waiting for you on your desktop.