How to Install Windows on a Mac without Bootcamp Assistant?

When you post a question such as yours, it would serve you better to state that you have an Intel or Apple Silicon architecture Mac running a specific operating system version. That reduces the fishing expedition as to what specifically will work in your case.

I use the current version of Parallel's Desktop Pro 19.3.1 on an 8-Core, Core i7 27-in 2020 iMac. Parallels charges me around $120/yr subscription and I have Windows 10 22H2 and Windows 11 Pro 22H2 guests. Those guests are installed on an external Crucial X8 SSD (1050 MB/s) connected to my Thunderbolt 3 port. The iMac is running macOS Monterey 12.7.5.

Microsoft has only publicly sanctioned Parallels for running Windows 11 ARM on Apple Silicon Macs. VMware is now offering a free, non-commercial user license for their Fusion VM client, but very likely will want personal information that at minimum may result in ramped email SPAM. Nothing is truly free with these vendors.

The free Oracle VirtualBox VM is only compatible (their current data) with Intel Macs running Monterey or earlier. I quit using VirtualBox after several years for Parallels Desktop.

Stack Social has Windows 11 Pro licenses in the $25 range (today) and you should have a Microsoft account because an aspect of the purchase process requires one to sign into a Microsoft account so the license purchase is registered with Microsoft. I purchased Office 2021 for Mac and Office 2021 Professional Plus for Windows through them and never paid more than $35 each.

Microsoft Windows licenses are platform-agnostic and can be used for ARM or Intel.

If it is an Intel-based Mac, you could install Windows inside of a virtual machine and run Windows at the same time that macOS is running.

Parallels sells virtual machine software (Parallels Desktop) – and VMware offers a free personal-use license to use VMware Fusion Player. (Either way, you will need to obtain a legitimate copy of Windows.)

Without using bootcamp you cannot natively install Windows on your Mac. Why? Because Bootcamp supplies all the drivers needed for Apple hardware components (screen, disks, Bluetooth, etc.). Without those drivers Windows has no clue what hardware it is running or how to talk to it.

As others have pointed out the only other option is to install Windows in a virtual environment.

If you have an Apple Silicon Mac, then things are much more complicated and restricted.

It is possible to use the Windows ARM version with a Parallels' VM, but there are a lot of limitations & restrictions with this option (still requires a proper Windows' license). Both Microsoft and Parallels have some documentation on how this works and the various limitations & restrictions.

Another option would be to use the third party UTM app which uses QEMU at its core which is a free open source machine emulator & virtualizer to mimic different CPU architectures so you can run an OS for a completely different CPU architecture on an Apple Silicon Mac. With UTM you can install the Intel version of Windows OS (you will need a proper Windows' license). However, there are a lot of limitations....the performance will be slow since you are emulating a different system plus running a virtualized instance of an OS as well. Plus you won't have access to any GPU hardware acceleration. For some apps this option may work fine, but for others it will be insufficient.

There is no Windows Bootcamp option for an Apple Silicon Mac so there is no way to run Windows on bare metal on an Apple Silicon Mac.

minecraftiaMACUser100 wrote:

I don’t recall being asked any. I just went through the thread to confirm this.

Apparently no one is telling anyone what they have for hardware, but expect answers to questions that need to know intel vs Apple Silicon (M1,M2,M3,…).

If intel, Boot Camp is only option.

If Apple Silicon, a virtual machine is the only option.

After that, it is buy a Window based system.

As already stated if you have an Intel Mac you could use a program like Parallels. I use that and have three different Window versions running (XP, 7 and 10) and they all work fine within Parallels.

Tru to use parrel. Its a simple app for mac.

minecraftiaMACUser100 wrote:

People have gotten Windows to work on Intel Macs without the use of Bootcamp, so I know it’s possible, I believe this is basically how it was done originally, when bootcamp was in its infancy, it used to be a lot more manual.

I know it can be done, we- ok maybe not we, but I, myself, am just looking for the instructions on how to do it.

I suggest that you contact those people. Apple provided Boot Camp to install Windows natively. Apple does not support "hacking". I have used Boot Camp and Windows on dozens of Macs. I know of no other legal/supported way to install Windows natively. Use a virtual machine if you need to install a Windows version that is not supported by Boot Camp.

minecraftiaMACUser100 wrote:

uh… no..?

The drivers have absolutely nothing to do with my inquiry. I’m sure they’d work perfectly after installing Windows.

It appears you do not understand drivers and hardware and their relationship/interface. Drivers have everything to do with an operating system installation on computer hardware. Windows does not include Mac hardware drivers and Macs do not include Windows low level software. This is why Boot Camp worked. Boot Camp provided the necessary interface.

Get yourself a Windows computer if you need to run Windows. I have several Windows computers that all work great. I also have Macs running Windows in VMs without issue. I also have Windows running in Boot Camp on a couple of Macs without issue.

But you NEED bootcamp to get the intel Macintosh hardware drivers that Windows needs to understand unique Mac hardware. Microsoft does not provide those drivers, so you cannot easily install Windows on a Mac without Boot Camp.

You could maybe dig into Boot Camp, find the drivers, and somehow get them into your Windows image in a partition, but all of that is on you to do, as apparently no one in this thread has that answer for you, and if someone that follows Discussions.apple.com does know, they apparently are not following this thread.

Maybe Google (or your preferred search engine) can help you.

minecraftiaMACUser100 wrote:

The problem with this is that Windows WILL NOT install onto the disk because it needs MBR on the destination disk,

having MacOS 10.8.5 on one partition and MacOS 10.13 on another partition, and Bootcamp not even trying to do anything when there are already 2 partitions. I'm trying to install Windows on a 3rd partition.

trying to simply reinstall it on that same partition would say that the disk is "of the GPT partition style". Whoever made this a thing needs to go under the jail, but I really need to do this. Any ideas?

I had to remove a bunch of text from your earlier post here in order to even make sense of the situation. It appears you have a Mac model from around Late-2009 to 2011 based on the two operating systems you mention.

Bootcamp Assistant was only designed to be used with one macOS installation on the internal drive.

If you insist on wanting two macOS installations and a Windows installation, then you will need to learn about the hybrid partition scheme used by Apple. Perhaps there is some older documentation online somewhere which will give you some clues. You can also experiment with installing just one Apple OS and using Bootcamp Assistant to install Windows, then closely examine the drive layout so you can try to recreate that layout manually. More than likely you will need to familiarize yourself with the command line and various command line utilities as well.

I'm not certain, but I don't think macOS has used hybrid partition layouts for some time now so it is doubtful you will find anyone who is able to assist you since they would also need an older system & access to an older version of Windows which requires a valid license key (AFAIK, Microsoft turned off the activation servers for older versions of Windows). Sometimes you just have to dig in and perform the research & analysis yourself.

FYI, your best option to installing Windows onto a GPT partition is probably Windows 7 since it should support both GPT partitions and UEFI booting which should make things easier since a Mac's firmware is very basic and is meant mainly to be used with macOS. I don't know how you can use a legacy MBR bootloader on a Mac since that must be some of that Bootcamp Assistant secret magic sauce. I've managed to figure out a lot of boot issues with various operating systems over the years, and I have no clue how this would be done. It has to be some special Apple utility provided by Bootcamp Assistant.

Another option would be to install just one version of macOS onto the internal drive and use Bootcamp Assistant to install Windows. Then install the 2nd macOS onto an external drive. Yes, the external drive will boot & operate slowly due to the USB ports, but it may suffice depending on how you utilize that 2nd macOS. Or perhaps you can run the 2nd macOS in a VM.

Keep in mind people who successfully installed Windows on a Mac without using Bootcamp Assistant probably did so without any existing macOS installation or they only installed later versions of Windows which supported both GPT partitions and UEFI bootloaders.

Either you will need to do the research & work to figure it out on your own, or you will need to ask those people who you say successfully installed Windows onto a Mac without using Bootcamp Assistant as one of the other contributors already suggested for the latter option. Obviously no one who has seen this thread has ever tried it.

minecraftiaMACUser100 wrote:

hmmm hybrid partition scheme… that sounds very promising. I did try installing each one manually, and first installing Windows, then making partition(s) for MacOS to be installed on, but as soon as I Installed MacOS, Windows would no longer show up as a boot option.

Windows does not like having the partition layout change like that. If you can boot to the Windows installer to access its recovery/repair boot option, then you could try using the automated startup repair utility.

Well I love Windows 7 so that’s awesome. I doubt that would work on Macs from 2009-before, since UEFI was like 2010-onward I think for the most part. These ones are what I am most interested in doing this to though, so that’s fine.

All Intel Macs are using EFI booting. However, some of the first generation 2006 Intel Macs were 32 bit systems , while others were 64 bit systems (aka CPUs) using a 32bit EFI. Your best option is using the 2nd gen Intel Macs or later which use the Core 2 Duo CPUs (or Xeons), or the i5/i7 CPUs since they are all 64 bit (CPU & EFI firmware).

I wish I could use a FireWire 800 drive to install old crusty MacOS, then I could use it with… 80% of my machines really, but I recall the last time I tried this, the installer complained about it being a FireWire drive and would let me.

macOS should have no issues using a FireWire drive for booting. I used to have external macOS FireWire boot drives myself & never had any issues.

If I am successful in my quest, I’d have to make a video on it, and a guide for it. I’ll dig up some old crusty documentation, something’s gotta work.

Good luck, it is always nice when people are willing to document procedures & provide reference materials.

It is still possible to install Windows 10/8/7 on an Intel based Mac. For dual-boot, you can go with Bootcamp Assistant if it is available on your Mac. If not, then you should first make a Windows bootable USB on Mac and install Windows from the USB drive.

Here is a quick guide you can follow to create a Windows 10 bootable USB on Mac:

https://www.uubyte.com/online-help/iso-editor.html

After that, you should back up your Mac and erase the disk to MS-DOS FAT32 (Master Boot Recorder).

Finally, press the Option key to boot from the drive and start installing Windows on your Mac with Bootcamp.

The problem with this is that Windows WILL NOT install onto the disk because it needs MBR on the destination disk, MacOS REALLY TRIES to use GPT, which is extremely annoying, and the only thing I've been able to do to temporarily make this not the case is to just use Bootcamp which I can no longer do due to having MacOS 10.8.5 on one partition and MacOS 10.13 on another partition, and Bootcamp not even trying to do anything when there are already 2 partitions. I'm trying to install Windows on a 3rd partition. This is after I already installed Windows BEFORE I restored my 10.8.5 partition, so bootcamp would actually work, but as soon as I put the 10.8.5 partition back, Windows would no longer boot, and trying to simply reinstall it on that same partition would say that the disk is "of the GPT partition style". Whoever made this a thing needs to go under the jail, but I really need to do this. Any ideas?

No one looking to get help with bootcamp is running it on an Apple Sillicon Mac, so that’s moot and not worth mentioning.

Running with bootcamp is the only “real” way to go. Parallels is a joke and breaks compatibility with many applications and software, let alone games, which is what I’m trying to use Windows on this Mac for. One really needs to run Windows on bare metal (not the API), and I don’t think parallels can do that, and since this discussion is about bootcamp, there is no reason to entertain such software. You can’t even run Ultimate Doom Builder!

I would know, I did try it on my fully maxed out i9 MacBook Pro, my M2 Pro Mac mini, my M1 Mac mini, an M1 MacBook Air I no longer have, my 16-inch 2021 MacBook Pro, and my 14-inch 2021 MacBook Pro. Complete garbage tier Windows installation on all of them. Windows is already horrible, making it go through translation layers is a terrible idea, plus Windows 11 sucks more than the rest. I would never use such a garbolium tier OS. My main gaming PC runs Windows 10, which is bricking itself as we speak. Not even kidding.

boot camp, however, does a lot of checks to ensure compatibility with your INTEL MAC, but sometimes that gets in the way of actually being able to do anything with it. That has happened many times to me, as did it now bringing me to this page. What we need is someone to tell us how to MANUALLY do the steps that boot camp assistant does on its own like partitioning, doing the GPT to MBR magic which is the part I couldn’t figure out, EFI stuff, things like that. I can’t speak for OP but I will never touch Parallels again and that’s not a real solution.