I just learned the hard way that once you install a new hard drive into a Playstation 3 that the old one will no longer be accepted and will need to be formatted to be used again.
Yesterday I bought a 250 gig Western Digital 2.5" hard drive for my PS3. I turned on my Playstation and attempted to backup my game saves and media (videos, mp3's, pictures) through the system menu. I needed 41 gigs to do so but I did not have this space available on any removable media. No problem I thought, I would just connect the drive to my computer and copy it that way.
I put in the new hard drive, formatted it and then plugged the old one into my PC. Much to my surprise a PS3 formatted hard drive cannot be read by either Windows XP or Vista - apparently it uses some sort of proprietary file system, I'm assuming to prevent any sort of illegal copying.
Anyways, I put the old hard drive back in only to be told that I needed to format it to use it. WTF?! After installing the new hard drive, the original 80 gig hard drive that it came with was no longer accepted and needed to be reformatted to use again!