Recycling iMac (2009) File Vault?
I am trying to safely recycle my daughter's iMac (2009). I have signed out of I-Cloud etc and switched off location services. I also switched on File Vault, but was unable to erase the drive in Disc UtiIities as it was greyed out. I switched the computer off and am now having difficulty in getting back in using the recovery key code as it wants me to reset my daughter's password and I do not have my daughter's gmail password nor her Apple ID.
Have I already done enough to make the computer safe to recycle by switching on File Vault or do I now need professional help?