Want to put Windows 10 or MacOS on a IMAC with corrupted HHD

Solution 1:

You model Mac supports OS X 10.6.6 through macOS 10.13.6. Usually you can download macOS 10.13.6 (High Sierra) using another Mac from this Apple website. You can then create a flash drive installer using the instructions given on this Apple website. If this does not work, then other options can be found here.

Officially, your Mac supports 64 bit Windows 7 through Windows 8.1. The easiest way to install Windows 10 is first use the Boot Camp Assistant to first install Windows 7, 8 or 8.1, then upgrade to Windows 10. This requires Windows 7, 8 or 8.1 to exist on a DVD and that the Mac has a working optical drive.

If you try to install Windows manually, then note the following.

• The Boot Camp Assistant will install Windows to BIOS boot. You can try to UEFI boot Windows, but this may lead to driver problems.
• The Windows Support Software for 64 bit installations of Windows 7, 8, 8.1 and 10 for your model Mac can be found at Boot Camp Support Software 5.1.5621. You can also download this software by using the Boot Camp Assistant.
• Many answers have been post here at Ask Different for installing Windows on on Intel Macs. For example, see How to install Windows 10 into a 2011 iMac without using the Boot Camp Assistant, an optical (DVD) drive or third party tools?