A clean install of the current Windows 11 Pro release (Version 22H2) is possible for all three Macs.
Activation will occur automatically after an administrator account linked to the same Microsoft account used for Windows 10 is added. In other words, Windows 11 can be activated for free.
The install can be done with only tools provide by Microsoft and Apple. No software needs to be downloaded from URLs other than those used by Microsoft and Apple.
I have a machine with Windows 11 Pro installed. The Direct X Diagnostic Tool (dxdiag.exe) reports WDDM 2.0. However, when I use Microsoft Remote Desktop to access the same machine from another machine, the Direct X Diagnostic Tool reports WDDM 1.3. So, I conclude Windows 11 must to some degree be designed to accept a WDDM driver that is less than 2.0.
When dealing with processor compatible issues consider the following. The table below was constructed using Microsoft's Windows Client Edition Processors table and and Apple's websites pertaining to Windows 7, 8.1 and 10.
|
iMac (21.5-inch, Mid 2011) |
iMac (21.5-inch, Late 2013) |
Mac mini (Late 2018) |
| Procesor |
I5-2400S |
I5-4570S |
I5-8500B |
| Compatible Windows Editions according to Microsoft |
none |
Windows 10 Enterprise LTSB 1607 |
Windows 10 1709 through Windows 11 version 22H2 |
| Compatible Windows Editions according to Apple |
32 bit Windows 7 and
64 bit Windows 7/8.1 |
64 bit Windows 7/8.1/10 |
64 bit Windows 10 |
| Compatible Windows Home or Pro Editions according to both Microsoft and Apple |
none |
none |
All since model's introduction date |
For both iMacs, there are many Windows editions which Apple states are compatible. Yet, Microsoft states the Mac's processor would not be compatible. From this, I conclude that just because Microsoft states a Mac's processor is not compatible does not absolutely mean Windows 11 Home or Pro editions can not be installed on the Mac.
The latest release of the Windows Support Software provided by Apple for each Mac should used to install Windows 11. In this case, the software is probably different for each of the three Macs. To be sure of using the latest version of the Window Support Software for a given Mac, the software should be downloaded by using the Boot Camp Assistant on the given Mac.
Actually, the Windows Support Software for any Intel Mac can be downloaded from Apple by using virtually any machine with OS X, macOS, Windows or Linux installed. However, the procedures for do so are beyond the scope of this answer.
Note: Do to a faulty assumption made by the author Tim Sutton, Brigadier does not always provide the most current version of the Windows Support Software for a given Mac.
This procedure makes the following assumptions. If any of these assumptions are not true for your Mac, then post a comment or ask a new question referencing this post.
The steps for installing Windows 11 are given below.
Determine the Windows 10 boot method:
Note: Windows 11 should be installed to use the same boot method as Windows 10.
If the boot method is already know, then proceed to the next step. Windows 10 will be using either a BIOS or UEFI boot method. The method can be confirmed by the location of the BCD file. For a BIOS booting Windows 10, the hidden BCD file can be found in the hidden Boot folder on the NTFS formatted volume labeled BOOTCAMP. This location can be checked from macOS or Windows by using the commands below.
If the BCD file is not found, then the UEFI boot method can be assumed. Or, UEFI booting can be confirmed by verifying the existence of the file EFI/Microsoft/Boot/BCD on the unmounted FAT32 formatted volume in the EFI system partition.
Create an USB flash drive installer: Start by downloading the latest Windows 11 Disk Image (ISO) file. For the example given in this answer, the "English (United States)" language was chosen, which resulted in the file Win11_22H2_English_x64v1.iso being downloaded.
Note: Using the Media Creation Tool can result in the download of a different ISO file. This answer was only tested using the ISO file downloaded without using the Media Creation Tool.
Also, use the Boot Camp Assistant to download the Windows Support Software for your Mac. This should be done from the same Mac where Windows 11 is to be installed. Copy the contents of both downloads to a MBR partitioned, ExFAT formatted USB flash drive labeled W11Install. If there is a file named AutoUnattend.xml, then renamed this file NoAutoUnattend.xml. Below is a macOS High Sierra Finder view of the files and folders in the root folder of this flash drive for the 2011 and 2013 iMacs. (Note: The Windows Support Software for the 2018 Mac mini does not have a file named AutoUnattend.xml.)
Open a Command Prompt window:
If the Mac has a T2 chip, then make sure the Mac is allowed to external boot.
UEFI boot from the USB flash drive, by restarting the Mac and immediately holding down the option key until the Mac Startup Manager icons appear.
Note: To proceed at least the keyboard or mouse needs to work. If both are wireless and fail, then you will need to find at least one working wired keyboard or mouse. If the keyboard only fails, then use an on-screen keyboard. If the mouse only fails, then navigate using the keyboard. Once in Audit Mode you can pair the failed wireless keyboard and/or mouse.
Select the external drive icon labeled EFI Boot. Proceed with the installation until the window shown below appears.
Note: Reaching this window causes drivers in the $WinPEDriver$ folder to be automatically loaded.
Next, select the red button with the white X or press the key combination option+F4. In the popup, select the Yes button. Next, select "Repair your computer", "Troubleshoot" and "Command Prompt", in the order given. This opens a Command Prompt window titled "Administrator: X:\windows\SYSTEM32\cmd.exe".
Install a clean Windows 11 Pro from the flash drive:
The table below shows the drive letters assume by this answer to be assigned to the following volumes.
| Ltr |
Label |
Fs |
Description |
| C |
BOOTCAMP |
NTFS |
Volume where Windows 10 is installed. Label shown is the default assigned when the Windows Support Software is installed. There also could be a different label or no label. |
| D |
W11Install |
exFAT |
Volume on USB flash drive containing the Windows 11 installation files and folders. |
Note: If either these volumes on your Mac are assigned different drive letters, then make the appropriate drive letter substitutions when entering the following commands.
Enter the following commands to format drive C: and (if necessary) assign the drive letter S: to the volume in the EFI partition.
diskpart
list volume
select volume c
format fs=ntfs label=BOOTCAMP quick
Enter the command below to exit the diskpart command.
exit
Enter the following commands to copy files to drive C:, where Windows 11 is to be installed. Here, /index:6 was used to select the installation of Windows 11 Pro. Use the output from the first command below to determine which index you should enter, then (if necessary) make the appropriate substitution when entering the second command.
dism /get-imageinfo /imagefile:d:\sources\install.wim
dism /apply-image /imagefile:d:\sources\install.wim /index:6 /applydir:c:\
dism /image:c:\ /add-driver /driver:d:\$WinPEDriver$ /recurse /forceunsigned
Choose to enter the following commands to install any necessary boot data, files and folders.
Choose either method given below to shut down the Mac.
Boot to Audit Mode: First, leave the Mac disconnected from internet. From the Mac Startup Manager, select to boot Windows from the internal drive as the default. (In other words, hold down the control key when selecting Windows.) After booting to Windows 11 on the internal drive, enter Audit Mode (by pressing the key combination control+shift+F3).
Install the Windows Support Software and updates from the internet:
If there are any unpaired wireless devices (such as a keyboard or mouse), then pair these devices before or after installing the Windows Support Software and rebooting.
Open D:\BootCamp\setup.exe to install the Windows Support Software. When asked, do not restart the Mac. Instead, connect the Mac to the internet and open the Apple Software Update application. Update Apple Software Update before updating any other items. Apple Software Update may need to be updated more than once. When the are no more updates to Apple Software Update, install the other updates, which will probably include one or more updates to Boot Camp. Do not restart the Mac until all updates have been made. Afterwards, restart the Mac. Finally, install all updates (including optional updates) offered by Windows Update, which may require restarting the Mac one or more times.
Note: If the file D:\NoAutoUnattend.xml exists, then you may elect to examine the file to see if Apple intended to have other files execute before D:\BootCamp\setup.exe. When testing this answer, I did not elect to do this.
Leave Audit Mode and setup the Mac for the Out-of-Box Experience (OOBE): From the the System Preparation Tool, select the options as shown below, then select the OK button.
Finish the installation: Turn on the Mac and followed the instructions. Among other tasks, this step will create your user account.
Windows 10 was activated before installing Windows 11. The result was an automatically activated Windows 11, as shown below. In other words, I upgraded for free.
