I had the same issue. After surfing the internet and testing several complicated methods, I finally found a solution to another problem that takes this over. The method is simple and tricky: manipulating a Windows 10 installation iso file to install Windows 11 instead. This will also jump over the TPM checking and no need to run regedit!
Below is a copy of the posted solution. Note that the author (Apple Support Community user MacWindowsOS) states that what is posted below came from Reddit.
[Guide] Windows 11 clean install through Boot Camp Assistant
Trying to install Windows 11 through Boot Camp Assistant (BCA) with an official Windows 11 ISO simply results in the assistant failing with the error message "Couldn't download Windows Support Software because it is not currently available from the server". This is because the Windows Support Software not only contains drivers for installing within Windows, but also contains drivers that are used during the Windows Pre-Installation Environment (WinPE), and Apple doesn't have drivers for Windows 11. Switch to a Windows 10 ISO, and the problem goes away - but then you're installing Windows 10.
We are able to workaround this issue by retaining WinPE from the Windows 10 ISO, but using the OS install archive from a Windows 11 ISO. This allows you to install Windows 11 on your Intel-based Apple device using the Windows 10 installer. This method also bypasses both the TPM and Secure Boot requirements.
You need the following:
Once you have all of that, do the following:
Create a folder somewhere in your computer (for simplicity, I'll just assume you're creating it in your downloads folder) and name it
Win11_21H2_BC (or similar, it doesn't matter what you name it)
Mount and open the Windows 10 ISO
Copy all files from the mounted disk image into the folder you created in step 1
Unmount the Windows 10 ISO
FolderCreatedInStep1\sources\, and delete the file named either
Mount the Windows 11 ISO
ESD-ISO\sources\, and copy the file named either
install.esd (most common) or
install.wim (less common) to
- If your file is named
install.wim, rename it to
Unmount the Windows 11 ISO
Open ImgBurn, and select Create image file from files/folders
In the top window, select the icon that looks like a folder with a magnifying glass over it (Browse for a folder) and select the folder you created in step 1. Don't open it, just select it.
Then, to the right of the destination input box, click the same folder/magnifying glass icon and set a name and location for your output ISO file.
Click the large folder to disk image icon. You will receive a message telling you that you've "only selected 1 folder". Click Yes.
Another message box will then pop up - Set the volume label to whatever you want or leave it as the defaults. The program will then create your modified Windows 10 disk image, and play an obnoxious sound effect once it's complete.
Then, transfer the disk image you just made to your Apple device. You can now follow the standard procedure to create the Windows partition and download the support software. Note that when your device boots into the Windows installer, it will be the Windows 10 installer. This is fine. It will install Windows 11, not Windows 10.