Hey folks - recently bought a slightly old (2011) model imac for work and it arrived without the original snow lion disk and a wiped hard drive . Not having used a model this old I borrowed a snow lion install disk from a co-worker so I could boot it. As this wasn't the original disk it didn't work. Grumbling I made a usb install disk of mavericks and plugged it in. The problem is the machine REALLY wants to use the disk. It's not letting me eject it (I've tried holding down left keys and option keys when starting up and using the keyboard eject). As such it's locking the disk in the drive in install mode and ignoring the usb. Leaving me with a lovely but useless paperweight. Anyone got any advice on how to a) get the old disk out b) point it to the usb assuming hitting option at the beginning does nothing? Thanks in advance!