Windows 10 on a Mac


For some reason I expected installing Windows on a Mac to be relatively easy, with Bootcamp providing some kind of streamlined, easy delivery method.


First step - download Windows 10 ISO from Microsoft. DONE.

Next? I read you should burn the ISO to a DVD. Ok - except - Not Ok - the latest instal file is too large to fit on a DVD.

Can you copy the ISO contents to a FAT32 formatted USB stick and then boot from that? No - some of the contents of the ISO are larger than 4GB, and thus wont copy to a FAT32 disk. You need to use ExFat. But even then - the USB stick will not be bootable. I thought the olden days of Macs was frustrating with needing a blessed system folder… but this is painful.

I turned to Bootcamp… but as the MacPro5,1 that I am trying to instal Windows 10 onto is only running Sierra, Bootcamp 6.0 will not work. It only goes up to Windows 8. I need v6.1 - which I have on my Mac Mini - but, I can’t just copy v6.1 to the MacPro - the app will not run under Sierra. So I move to the Mac Mini to try to finish creating the instal USB…

However - when I try Bootcamp 6.1, with the Win10 ISO file, and a USB stick, it says there’s not enough space. So, I pull the SSD out of the MacPro, run it via a USB-dock on the Mac Mini. It is a 500GB SSD. But, Bootcamp STILL says there is not enough space.

This is apparently a common complaint. The issue apparently is either that one of the partitions that Bootcamp creates is too small for what the latest Win10 needs, and/or when Bootcamp tries to create a temporary cache on your start up drive, it needs contiguous space, and even though my startup has 70GB free, it gives the space error.

All the while having a 14yo harping “is it working yet, is it working yet?”

Give me strength…

Cosmic, The Mac Pro 5 1 will run Mojave without tweaking / patches, and so with that can run the latest version Parallels Desktop 18 software. You’ll need an earlier version if you want to stick to Sierra on the 5 1.
I’ve been using Parallels since 2006 on Intel Macs.
It’s seamless operation is great, albeit you need another software licence. Flip between Mac Windows or Linux at will without rebooting, have a couple of different OS’s running simultaneously, - you just need sufficient RAM and drive space.
worth considering ?

Check VMWare Fusion - or the free Oracle Virtual Box, but VB may not support the software you want to run.

I run the subscription based pro edition of Parallels now on my i9 laptop and give the VM 24GB of RAM - Home edition only allows 8GB RAM for the VM.
Parallels will also run down to Mac OS 10.7 Lion in a VM for older 32 bit software.
I’ve got a Lion and a High Sierra VM on disk for occasional use too.

They bleed you for the annual upgrades if you need or want them, or same for the subscription version, - but that’s where they are all going now to get a guaranteed revenue stream.

Installing a guest OS into a new VM is quite straightforward on Parallels too.

Dare I suggest you buy a cheap Windows laptop?

Vmware fusion player is free for personal use. So if you have a Windows licence, you can run Windows on a Mac for free.

I have used VMware on a Mac for over a decade, paying for the original licence and for upgrades. Then they released the free player licence. Brilliant!

I gave up trying to install Windows 10 on my 2010 Mac Pro & it was running Catalina at the time. I run Windows 10 under the free VMware Fusion on my MacBook Pro. It runs ok. I managed to install Windows 10 to a USB SSD via my MacBook Pro & it leaves the the emulated version for dead as far as speed & usability go…

Snarl, VMware Fusion Player sure looks the goods for home use. No hardware limitations like the 8G memory limit for a VM on the Parallels Desktop Home version, - and it’s free !

At least my Parallels Pro subscription is tax deductible though… :sob:

It’s for my son til he can save up for a “gaming” pc. I’m assuming running Win10 “natively” will perform better than VM…

Mojave was like treacle on the Pro.

Can’t believe just getting the Win ISO onto either a usb or SSD could be so hard.

I tried numerous things over & over & like I said, I just gave up in the end…

I was using an M2 PCIe SSD at the time & a Radeon 580.

Now that you mention Mojave, I might have tried it with that as well.

Look up Open Core Legacy Patcher (OCLP).

Boot loader support with modern video cards + native windows support.

I decided to go M1 instead…

I was responding more to @cosmichobo – to get Windows onto a Mac Pro 5,1.

I’ve got a 5,1 in my garage with an RX580. I only turn it on when gaming – and then I connect from my M1 Pro 16-inch using Parsec. It’s great.

Hi @jaysee

My son wont accept Mac OS… primarily at this moment because it wont run some steam submarine game he wants to play… but generally because his friends are all on PCs, so it’s easier if he is in the Windows environment.

The problem isn’t booting the computer into Windows - I can’t even get the Windows installer ISO loaded onto a USB stick, in order to attempt to boot the computer.

Once we get that far, we’ll be able to see if it can run the games he’s wanting to run under Win10 “as is” (ie with the existing hardware)… or whether it’s better back under Mac OS. If that’s the case, we’ll go up to High Sierra, but Mojave was useless.

I think he’ll be better off long term to save his money for a 2nd hand PC, than to look at upgrading the graphics card etc on the Pro. It was really just meant to be a cheap easy way to get him a “PC” until he can save enough money to get something reasonable.

I use parallels. Easiest way for me to access it when I need to.


My son has a Lenovo laptop. Running windows (x). I’ll see if that helps the workflow. Wonder if I can just run the installer from the laptop, with SSD connected via USB dock…

Just a thought… If you take the optical drive out, you might be able to install windows just from a disk image. I don’t know if that will make any difference. I was going to say have a look on YouTube but I guess you would have already done that.

My comment was about how to get Windows 10 with boot screen support on a 5,1 with a newer gpu.

Yeah it’s really confusing. I’ve been looking on YouTube and various sources, and there’s a bunch of different instructions just within the past 2 - 3 years based on various recent changes to things like the ISO instal file size (now too big for a DVD), and the fact that there’s now file/s in the Installer that are more than 4GB, so you can’t format the drive in FAT32 which is what most of the manuals say…

I’ll check out the Lenovo idea tomorrow… hopefully that’ll solve the issue as it will hopefully be able to run the ISO - just so long as the Lenovo can read from my USB hdd dock…

I used this to put Linux onto my 2010 MacBook. No doubt it would do Windows as well… but it might not do it the way you want. I gave over the entire computer to linux, rather than trying to dual boot. Also, it might not work on your hardware. Worth a look?

Thanks! I didnt know about this, and have lond wanted to run Windows Steam on my iMac, but thought those days were gone once we lost Bootcamp.

I installed Windows 10 onto an external SSD from my MacBook Pro using VMware Fusion just from a guide on YouTube. That was easy enough.