Q: reformatting laptop ("couldn't unmount disk")
hi all,
i gave my 2009 MBP to my mom and reformatted the disk. she didn't use it and i tried to reformat it so i had my name and ID on it and ended up having to bring it to the genius bar because i wasn't able to get the PARTITION tab to "un-grey out". turns out i had to OPTION BOOT into the recovery hard drive in order to reformat the user drive (or whatever this is called).
the problem is that i brought it home and it had a login password that i wasn't able to remember.
so i figured i would go in and REFORMAT by OPTION BOOTING into the recovery hard drive.
now when i go to the PARTITION tab i try to reformat to a single partition and i get a "couldn't unmount disk" error.
can anyone help me figure out how to get this drive back to a fresh install with no login so i can get working with it again?
thanks in advance
MacBook Pro, OS X Yosemite (10.10.5)
Posted on Mar 9, 2016 7:57 PM
You can try and use the original installation disk of your operating system to format your drive or you can make a bootable USB and reformat your drive from there. By booting into something else than the computers harddrive you can circumvent the unmount disk error.
Create a bootable installer for OS X - Apple Support
https://support.apple.com/en-us/HT204904
Use the version of OS X that came with your Mac, or a compatible newer version - Apple Support
Hope this helps!
Posted on Mar 10, 2016 12:30 AM