In order to open your photo-book, you should use the program that created that file. If you don't know what program was used to create the file, right-click on it, select Properties and open the General tab. Copy the format next to Type of file and paste it on Google. After that, download and install the programs suggested by Google. If you already have on your computer the program used to create the file, but it doesn't open the photo-book, try uninstalling and then reinstalling the software. This should fix it.