Installing Windows 11 on really old MacBook Pro’s – actually any old computer


Windows 11 is here. And I like it. I use(d) Windows 10 daily so what does Windows 11 give me that I don’t already have. In short, nothing.

But Windows 11 looks more human. Rounded window corners. And properly grouped settings designed with the aim to make them easier to use on a tablet or touch enabled computer. And a little more colorful icons here and there. Especially the Windows Explorer has been given an overhaul to make its look more sensible.

The Start Menu in Windows 11 is nice, including a Pinned section ( app icons listed as on any mobile phone ) and a Recommended section ( listing recently accessed files ), but its section to access all applications installed is still as primitive and flawed as it has been since Windows 8. But fortunately the help is not far away. Just install Open-Shell and you are right back to the good old Windows 7 Start Menu. And now it is even better. In Windows 11 the icons on the Task Bar is centered as macOS also does. Which leaves the space open in the left side where the Open-Shell Start Menu will be located. So you are free to use ( and compare ) a proper Start Menu like Open-Shell and the one included with Windows 11. That is a brilliant move by Microsoft.

So how to install it. Microsoft initially introduced some over-the-edge requirements eliminating all computers older than 4 years. They have since relaxed some requirements, so now allowing most computers made for that last 8 years or so to be officially upgraded.

I will introduce a little fiddling with the installation media that will allow Windows 10 to be upgraded on most any computer. Why is that a good idea. Because I like the old MacBook Pro’s from 2011 and 2012. But they don’t have any TPM module ( required ) and the disk uses a hybrid MBR disk partition management that is not GPT ( required ). And they don’t support Secure Boot ( required ). So they are really incompatible in any way imaginable. Yet it can all be ignored.

The procedures described is for Windows 11 21H2 Pro build 22000.194 released October 2021. The first official ( multi edition ) version. It can be downloaded here :

Use the version in section Download Windows 11 Disk Image (ISO).

The starting point is a computer updated to nothing higher than Windows 10 21H1.

Update : It seems Microsoft discovered the loop-hole and closed it. The procedure does not work with Windows 10 computers updated since mid October 2021 or so. Pitty.

Upgrading a quite modern computer ( 4 to 8 years old or so )

The single step needed to allow a computer having an aged CPU is to insert this information in the registry ( google it for the procedure ) :

Windows Registry Editor Version 5.00



With that information in place a Windows 11 installation medium will perform an in-place upgrade to Windows 11 21H2. Simple as that. There are a few requirements still in place. TPM 1.2 or newer must be present and the other Microsoft artificial requirements.

Upgrading a very old computer

The steps needed to upgrade a really old MacBook Pro is surprisingly easy.

Mount the ISO file and copy the content of the Window 11 installation medium to a folder on a partition.

Locate a file in the Sources folder called appraiserres.dll. And delete it.

Then run the Setup.exe file to perform the upgrade to Windows 11. The installer will not prevent the installation. Simple as that.


Whether it is a good idea to install Windows 11 on such old computers is a personal judgement. Microsoft says you should not and did its best to prevent you from upgrading. Addition June 2022 : Windows 11 still works without issues.

The reason should be for security reasons. But the old computer runs just fine without the availability of the security options.

Remember a complete system backup every now and then. Just in case Microsoft tricks you in a later update.

The nerdy stuff – and Rufus

Microsoft has their own ways.

When you install from an USB stick, which most does, then the stick must be formatted. Either as NTFS or FAT32. But you cannot select freely which to use.

If you install to a computer booting in UEFI mode then the format must be FAT32 as the UEFI bootloader does not support NTFS. Lazy Intel decision.

If you install to a computer booting in MBR ( aka legacy mode ) then the format can be either of these.

If you download a Windows 11 USB stick installer from Microsoft then the installer will create a stick formatted in FAT32. If you look into the content of that stick you will find a large install.esd file being Bytes large. Important here is that it is slightly smaller than the 4GB file size limit imposed using FAT32. So this stick can be used on any requirements compliant computer to install Windows 11.

However if you download an ISO image file intending to upgrade a computer to Windows 11 then its content will be slightly different. If you look into the content of that ISO file you will find a large install.wim file being at least Bytes large. Important here is that it is larger than the 4GB file size limit imposed using FAT32. So this ISO file cannot be copied to a FAT32 formatted USB stick. Meaning such a stick cannot boot with a computer set to UEFI boot mode. The reasoning behind this is odd.

Now to the funny stuff. There is a bright programmer who has corrected this oddness. He has made a ISO to USB stick copying program called Rufus. This program does something normally not possible. Creating a bootable USB stick with 2 partitions. A small FAT partition and a large NTFS partition. The FAT partition contains a NTFS driver for the UEFI bootloader. Allowing UEFI to boot from the NTFS partition which can handle the large install.wim file.

In this way you can boot from a Windows 11 ISO image no matter what boot mode the computer is set to. At least as long as Secure Boot is not interfering in unexpected ways. If so then disable Secure Boot while installing.

Note, you still need to make the USB stick for the computer configuration used, UEFI or MBR.

Rufus has also made provisions to install an “enhanced” Windows 11 version on non quite compliant computers.

Rufus is also usable simply as a ISO to USB stick copying program. Try it. The developer discuss its merit at length, here :