Good evening, I've an iMac mid-2010 2.93 quad with 256Gb SSD and 1Tb HD. I've rarely used my pride and joy recently, so reluctantly decided to sell it on. This morning, I started the wipe process by creating a bootable Sierra thumb drive. I then went on to erase the content of the 1Tb hard disk, booted in safe mode, and deleted the content of the 256Gb SSD with the intention of then rebooting from the thumb drive to reinstall OSX. With just seconds to go I got an error message saying OSX had failed to instal and to restart the process. Since then I have tried dozens of times to boot holding the option key, Cmd+R etc yet regardless of what I try, all I get I s the Apple logo and then the progress bar which creeps to the end and there it stops. I've googled umpteen scenarios and can't find a way out. I did at one point get internet recovery mode but nothing happened there after an hour of waiting. I've tried PRAM reset etc too but to no avail. I do have an Apple SuperDrive and an old copy of OSX on CD as even the built in slot keep spitting the disk out but I can't get that to work either. Does anyone, please, have any suggestions as to how I can fix this? Surely both disks can't be goosed? Any help greatly appreciated! Thanks in advance!