Upgrade the internal hard disk of my old iMac!

I want to upgrade my old iMac "Core 2 Duo" 2.4 20" (2007-2008) in order to use it again. I have successfully upgraded the memory from 1 to 4 Gb, and installed the latest supported version of Mac OS on the internal 250 Gb hard drive (10.11.6 el Capitan).

I have several "old" 1 Tb hard drives that I used on a PC and wanted to use one of them to replace the standard 250 Gb hard drive. But when I boot on the USB installation key, after a few seconds, I get the "stop" sign and nothing happens. I tried the different command / option / P / R keyboard combinations, nothing works. I even tried to change the disk type to GPT and create a partition (using DISKPART on my PC) ... nothing works, the installation stops :-(

The bootable USB key was created on my PC using DISKPART (GPT type + primary partition creation) and TransMac to "burn" the DMG file.

Can you help?

Thank you!


Posted on Aug 29, 2025 12:33 AM

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Upgrade the internal hard disk of my old iMac!

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