1.Go here and download this small free application: http://www.download.com/FastStone-Im...dlPid=10797071
3. Open your image with FsViewer (either right click the image and choose 'Open With' and navigate to where it says 'FSViewer' and open, or launch FSviewer and choose File Open and navigate to your image and open it that way)
4.Once Image is open in FSViwer, go to 'Edit', scroll down to Resize/Resample and click that.
5. Now if your image isn't already a perfect square in other dimensions, you'll need to make sure to deselect / uncheck 'Preserve Aspect Ratio' at the bottom. So do that.
6. Now at the top of the resize window, where it says 'Pixels' type in the Width text field 700, and int he Height text field 700. then click Ok. (You may want to take note of the Print Size resoution here as well - if you need the DPI to be 72 then enter 72)
7. Now your image is 700 x 700 and can be saved to whereever by using file, Save As and choosing a name for the file and place to save to.
Caveat/Disclaimer: The above method will turn your image into 700 x 700, but if your image started out say 800 x 300 then it will distort the image ratio badly strething and elongating it. If you want o prevent distortion then the Preserve Aspect ratio must be checked, but in doing so you wont get a perfect 700 x 700 image (if your image isnt already a square).
Hope that helps.
BTW If you have Photoshop CS3, that's even better and I can provide instructions in that how to perfectly align and optimize your image.