I got a retina 13" from ebay, arrived today. The seller hadn't wiped it, and also had a bootcamp partition installed. I don't have their password so I booted into the recovery partition, opened disk utility and tried to delete the Windows partition from there. I left it ages and it just said removing etc etc, so I quit disk utility, restarted and then went into disk utility again, selected the ssd to wipe it, but it keeps failing and saying can't unmount the disk. I subsequently got the seller's password but the bootcamp utility is no use as it's not picking up the partition. Now, it is currently instaling a fresh copy os OS X, but the ssd capactiy shows as 210GB rather than 250GB as the 40GB windows partition is still there somehow, even though it doesn't show in disk utility. Are there any apps, or is there a way to remove the bootcamp partition?!! There must be, but I don't know how. It's not even showing in disk utility, but it must be there as there is 40GB missing from the Macintosh HD?!