[Jozo]

For those that have the same problem here is a simple way to do this. I use windows but linux and probably mac have some similar way to do this.

1: Open a book on the Orizon to make it create a .dat file.
2: Connect the reader to your computer.
3: Copy that .dat file to the root of where the books are stored. Probably something like "e:\digital editions" It is a hidden file in the same folder as the books.
4: Open a command prompt.
5: Go to the folder where you have the books and type in at the command prompt:
dir /on /s /a-d >script.bat
This creates a list of all files that are in that folder and subfolders.
6: Open the newly created script.bat file in a text editor.
7: Now for some search and replace you want to convert the lines that look like E:\digital editions\Books\sample book.html ->
copy "your dat file.dat" "E:\digital editions\Books\sample book.html.dat"
Search and replace the following.
E: -> copy "your dat file.dat" "E:
html -> html.dat"
txt -> txt.dat"

Make sure to include the quotes since you want the filenames in quotes if there is a space anywhere.
7.5: Delete lines for files that should not have a .dat file. Only keep the html, txt and other file formats that you use. If you have .dat or .thn in the list delete those lines.
8: save and double-click the script.bat file. It should now make a copy of the .dat file for each file that you had.
9: the same procedure can be used to create a .thn file for thumbnails.