Did you look for it in your network Bottom section of File Manger - Labelled Network. My Network
Drive only shows up in the network since mine only connects to a network and has no USB connector. When you connected it to the PlayStation 4 did it in any way format or configure the drive to work with the PS4. If it did then it might of - formatted that Drive and now it will only work with the PS4. I would go to the WD Website to see if there is any Recovery software for your WD Live Book.