The "Initial Run Options" dialog that appears next is there to try to save you time by avoiding recopying files that may already exist on both Folder A and Folder B but have different date/times.

  • Consider files whose name and size match to be identical - You may want to use this option if there are existing files on both Folder A and Folder B that you know are the same but whose last modified date may differ by months or years. (This is the default option.)
  • Consider files whose name and size match to be identical only if the timestamps on A and B are within X (units) of each other - This option resembles the previous "Consider..." option except it gives to the ability to say that files older than a particular age need to be copied even if they have the same name and size. (A setting of "0 minutes" really make this option behave like "Simply copy...")
  • Simply copy all files from A to B - This replaces all files on Folder B with fresh copies of files from Folder A. As the label suggests, this option takes the longest of any of the three options.

If Folder A or Folder B is empty, your selection will have no effect. Files with the same name on Folder A and Folder B but having different sizes will always be overwritten, regardless of your selection. (Your selection only affects existing files with the same name and the same size.)