Windows 7 Explorer can't preview PDF files by default. If you want to know what the PDF file contains and the file name is not useful enough, the only option is to open up and see what's inside. But this is really inconvenient especially if there are multiple files you want to check one by one. Once you install the tool, it will automatically configure the explorer preview pane and the reading pane in outlook with PDF support. Here's how the preview of a PDF file in explorer will look like -.