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Picasa is an image editing program produced by Google, and it is available as a free download. If you don't have any image editing software installed on your computer, consider downloading Picasa. Resizing an image can be done in a few steps.  Click on the "Browse" button on the Export menu and select the folder where you want the image to be saved. " Move the slider to the right of this button to indicate the desired size of your image. Click "OK" and the image will be saved.

Summary:
Open your image in Picasa. Click on "File" from the toolbar, and then click on "Export Picture to Folder" from the menu that appears. Select the folder where you want to save the new, resized picture. Click on the radio button that reads "Resize to.