Can't wipe old 2008 iMac for recycling
I'm finally trying to wipe my old 2008 iMac (OS X El Capitan 10.11.6) so I can bring it to Apple Store for recycling. It's won't give me the Disk Utility option to erase! I have read through past threads and nothing works. I even have the original install CD-ROM which I've had inserted when I start machine and hold down control + R, or option, or option+ control+ R or option+control+C or C. (These have all been suggested in various threads.) Each time I just get my old sign in and normal screen.)
Can someone please help? I did sign out of icloud.