Chosen Solution
I have an iMac 7.1 (2.4 GHz Intel Core 2 Duo, 4 GB 667 MHz DDR). The serial number indicates it was introduced 8/7/07. Recently, after turning it on, after a short time it starts making a soft high pitched whine. When that happens, there is a perpetual turning wheel on the mouse pointer and nothing will respond. I have to reboot by turning it off by the switch. I’m using the OS it came with (Leopard 10.6.8). At this point I’m wondering if it’s worth it and how easy it would be to install a new hard drive and upgrade the operating system.
Here’s how to replace it: iMac Intel 24" EMC 2134 and 2211 Hard Drive Replacement First try starting up from your original system install disk and run Disk Utilities. You will need to do this to format the new drive also and install a system. You need to install the original, take it to 10.6.8. Then go to OS X 7.5 then you can go to El Capitan. BTW I just did a HD replacement one one of these this weekend. I used a 2.5" Seagate 500 GB SSHD in a adapter frame. The speed increase was really dramatic, surprised even me.
