Wonder if anyone can help me out. I am selling my old 2007 iMac with El Capitan on it. I just tried to erase the HD on it, and reinstall a fresh OS. When I get to the install prompts, it tells me to sign in using my apple ID to download El Capitan (I do), It goes through and prompts me that the item is not available, try again, I tried it again, again and again, still nothing. It keeps popping up that message. I have tried a search, but most of the threads drop off from the original poster, and never tells how its done. Does anyone know how I would proceed to erase this iMac so I can sell it ? I can use a backup to restore it, but that does not help me. I want to get rid of everything, so i can sell it. Plus, Is there a way, NOT to sign in using my Apple ID ? to do this ? Thanks.