If you don't have a graphics program to resize and crop images here's a fairly easy way to resize the gigapixel images in windows with good quality and no loss of image details. It may sound like it's complicated but if you do it a few times, it's simple.
Find and open the image with windows photo viewer.
Size the window to a reasonable size by grabbing and dragging the corners (to say 1/2 the screen width)
press and hold the ALT KEY and the print screen key (making sure you didn't click anything but windows photo viewer)
open microsoft paint (If you don't know where it is click START, RUN and type in mspaint or look in START/ALL programs/accessories)
Press the Control and V keys (this copies the printscreen into MSpaint)
Use the SELECT tool to mark the area you want to crop
press CROP and SAVE the newly sized image.
Why not just open your image using MSpaint (aka paint) and then click on resize in the Home menu, select pixel and change to 640 vertical x 480 horizontal (you only need to type in one, paint will figure out the other), then save. That way keeps the same height/width aspect.
You can also rotate your image using paint.
DM
