The default samples don't reload, but they are on the CD.
Your bought books are stored in one of the subfolders in the ConnSoft install, but you can export them by putting them on an SD with the ConnSoft, and then using Windows Explorer to copy them where ever. They do have really nasty filenames, but you can change that if you like without affecting the way ConnSoft sees them since it uses the embedded meta-data, rather than the filename.
And, of course, as LG says, you can re-download them from the ConnStore, but it gets to be a pain if you have more than a few of them.