If you are using windows, you will need to download and install ImageMagick.  ImageMagick is a free third party tool that handles the conversion of many different file formats.  Its used to convert the images to small thumbnails.

[http://www.imagemagick.org/script/binary-releases.php#windows]

I generally get the top link via HTTP.

[attachments|imagemagick_link.png]

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If you want to make thumbnails of PDF or TIFF images, then you will also need GhostScript installed.  Click on the latest release.

[http://pages.cs.wisc.edu/~ghost/]

Then click on either the 32bit or 64bit version.

[attachments|ghostscript.png]