To resize a photo:
-Check your camera settings. There are choices in the quality or what you want to do with the picture prior to taking a photo. When you change this setting it helps with the resizing.
If you don't want to change your camera settings:
-Put the photo on your desktop
-Dbl click it to open it
-SAVE AS
-At the bottom of my SAVE AS window I can grab a slider bar which allows me to save the picture in a smaller size
-Save the photo in that smaller size
HTH-