Cannot access vital boot options on Mac Pro with OS X Lion
Solution 1:
USE THE WIRED KEYBOARD - Maximus put me on the right path - my iMac wouldn't respond to the startup key sequences using the Bluetooth keyboard; the wired keyboard worked perfectly. My DVD drive doesn't work, so I tried making a bootable usb hard drive and then a bootable usb flash drive from my Snow Leopard Installation DVD, and couldn't get the iMac to see either of them, I thought, when actually the problem was the iMac wasn't seeing the startup key sequences from the Bluetooth keyboard. Something so simple...