I’m trying to install Mac OS X Lion after accidentally having erased my disk in order to reboot my iMac, which I did without backing it up. On a separate USB drive, I formatted and installed a Lion DMG file in order to reinstall the software back onto my computer, which currently starts up recovery mode because of my missing OS.
In order to download my OS from my USB into my hard drive, I believe I need to partition and erase my drive, however I get the error that the disk cannot be unmounted, most likely because the volume is being used? I have tried forcing the disk to unmount several times and have been stuck on this issue for days.
Please help. I just want to use my computer normally.