It's not a bad idea to backup the non-ebook files and folders to their own folder, as well. As mentioned,
it takes up hardly any space on a hard drive.
Just to set the record straight the Ectaco jetbook, which shares the same hardware, is using the same
Adobe Reader Mobile v9.1.1 as the libre, and handles .epub and .pdf exactly the same.
It is well worth it to get a USB 2 card reader for your PC, to work with your SD cards. The libre only
has the old USB 1.1 interface, and is much slower. SyncToy works very well with an SD card in a card