Hello all, I'm having some issues with my time machine/external hard drive that hopefully one of you kind people will be able to help out with. I'm not overly Mac literate, so simplicity in any responses would be really appreciated! I'll start from the start: I had been using a Western Digital external drive as a host for my time machine on my old 2007 Macbook with no problems. I recently made the switch to a Macbook Pro and went about using time machine to set up my new laptop. There turned out to be problem with doing this - the guy in the Apple shop tells me it was something to do with an new Intel chipset on the new Macbook Pro affecting the file export programme (which I can't remember the name of). Anyway, I was able to access and drag the back up files manually. But, then, as I tried to use the drive as a time machine for my new Macbook Pro, it would always say the the drive was full. I had been under the impression that it would delete old backups to make space for new ones, but this didn't seems to be happening. So, rather than keep wasting time, I just used disk utility to erase the drive and set it up again as the time machine for my Macbook Pro. Everything was working fine at this point. It started backing up no problem. It was going to take 3 hours or so. Unfortunately my girlfriend obviously had something mightily important to check on Facebook and casually removed the hard drive mid backup. When I tried to do the backup again, I was given this message: "Time Machine could not complete the backup. Unable to complete backup. An error occurred while creating the backup folder." So then I thought, ok, I'll just erase it again and start over. But when I try to erase with disk utility (in the format Mac OS Extended (Journaled)) I get this message: "Volume Erase failed: Volume Erase failed with the error: Couldnt unmount disk." If I try to go into the actual drive and delete the backup manually I get: "The operation cant be completed because an unexpected error occurred (error code -8072)" One forum I read recommended Repair Disk and then Repair Disk Permissions with Disk Utility, but when I try Repair Disk, I get the message: "Disk Utility stopped repairing System Back Up Couldnt unmount disk." It appears to me that the drive still thinks it's running time machine, or that the backup that was stopped half way has been corrupted in some manner. When I go into the drive and look at the backup file that was stopped, the file says that it's "in progress". That's as far as I can get. Short of trying to delete, switching off time machine, and unplugging the drive and restarting, I'm not really all that sure what to do. This whole external drive/time machine thing has been very frustrating and disappointing. I had been using it to backup work I'm doing for a PhD, so I wanted something reliable, but it's never actually performed the tasks it's supposed to since I bought the thing. If anyone can help, I'd love to hear from you.