Chosen Solution
I installed a new Hard Drive in my iMac 21.5 desktop, then used the original install DVDs successfully. There is no wifi icon to hook it up and in system preferences and clicking on network I can find no way to set up wifi. Also when I try to do updates, it Downloads them but won’t restart to install them. When I look up system updates like Yosemite they have black lines through them and I can’t even down load them. Help!!!
I called apple and they helped me do a disc image download of snow leopard. Then using the App Store they had me download El Capitan. It took a while but it installed perfectly. The only issue I have now is the wifi is missing and I cannot find it when I go to system network then to network. This is a 7 year old computer. Apple helped me for free. They said since it was a problem updating system they would help. They helped me for 2 hrs. They are knowledgeable and patient. Go Apple support.
Still need to know your exact model to get you to the correct guide. Sounds like you used a hard wire connection to do the download. Go under the Apple to about this Mac > System Report > WiFi and see if the Wi-Fi card is even being seen.
