Currently, this would be High Sierra (macOS 10.13.6). Install Windows using the latest version of macOS.The single internal disk in my Mac uses a 512 byte sector size. Use only one partition on the first internal drive ( disk0) for the Windows files.Boot Windows using the legacy BIOS boot method.I do not want to first install an earlier version of Windows and then upgrade to Window 10. Install Windows 10 into a newly formatted volume.I have downloaded the latest Windows 10 (Version 21H1) iso file. I have no problems EFI booting the USB Windows installer, but I still want to install Windows to use the BIOS boot method. I have always assumed the Windows Support Software, supplied by Apple for my Mac, was designed only for the legacy BIOS boot method of installation. Apple did not officially start supporting this method of booting Windows until after the 2011 model year. The resulting flash drive installer defaults to a Windows installation that uses the EFI boot method.The Boot Camp Assistant software has to be hacked in order to create the Windows installer.I have the following problems with doing this.

plist file contained within the Boot Camp Assistant software. This was accomplished by first editing a. I have read where others have successfully used the Boot Camp Assistant to create a Windows flash drive installer. If you have one of the models listed below, then you should use the Boot Camp Assistant to install Widows 10. The following Mac models support 64-bit versions of Windows 10 when installed using Boot Camp. The exact list of supported Mac models is given below. Staring in 2015 Apple starting omitting BIOS code from the firmware which ended the ability to BIOS boot from any type of drive.Īpple does not support Boot Camp Assistant installations of Windows 10 on 2011 and earlier iMac models. No Mac models older that 2011 can BIOS boot from an USB drive. The only 2011 Macs which can BIOS boot from an USB drive are the MacBook Air and Mac mini models. User fdmillion's answer requires a Mac that can BIOS boot from an USB drive.

Note the following regarding fdmillion's answer to this question

Macbook air 2011 bootcamp windows 10