I am running a non-retina 15' 2012 Macbook Pro with Mojave 1.14.4. I had some apps for work that I can only run on Windows but I am not willing to download the full Windows 10 with all the bloatwares that it has. So I found some reputable custom Windows 10 Lite iso files in hope of having a lighter version of Windows I could use without worrying about Windows update or all its bloatware. Though, Boot Camp Assistant rejected installing the file with this popup: .

The iso I'm trying to install is a 64bit iso as well and with some digging, I found that Boot Camp only allows installation of official Windows 10 iso files downloaded straight from Microsoft. Is there a way I could bypass this pop-up altogether and proceed with my installation? Or if there are any Windows 10 iso that works will be great. Worst case scenario I guess I will have to install the full Windows 10 iso. Thanks in advance.

  • There are no "reputable custom Windows 10 ISO files". Every one of them is against the license. Dec 30, 2021 at 17:43
  • @Marc: What make you think creating a custom Windows 10 ISO is against some sort of license? Microsoft provide various tools which OEM's use to customize Windows for the PCs they sell. Usually software is added. However, a custom ISO could be created where unnecessary software was removed. Dec 30, 2021 at 22:35
  • iranoutofideasfornames: You can use the Boot Camp Assistant to download the Windows Support Software, which contains the drivers for your model Mac. After that, you probably will need to install your version of Windows without further use of the Boot Camp Assistant. For what others have posted, I believe Windows should be installed to BIOS boot. However, since I have never had access to a non-retina 15' 2012 Macbook Pro, I can not confirm this. Dec 30, 2021 at 22:55
  • @DavidAnderson Because they can't legally distribute the result. Any right not explicitly granted is reserved to the copyright holder. Where would this custom ISO come from? WarezAreUs.com? Dec 30, 2021 at 23:03
  • How do you know these ISO files were distributed? This is not in the OP's question. For all I know, the OP works in an office and the guy next door made the custom Windows ISO. Or, maybe the OP made the ISO using a PC. Dec 30, 2021 at 23:33

1 Answer 1


Boot Camp will not let you install any Windows ISO that isn't directly downloaded from Microsoft. It is quite annoying, I know. So you need to use Bootcamp just to download all the Drivers and other files, which Boot camp does allow. Then you will have to make your own Bootable USB/DVD and partition your drive and then install Windows Lite.

  • ....yeah, that was what I compromised on. Until Boot Camp just screwed me over and doesn't allow me to install Windows Support Software even though I untick it, it keeps forcing itself upon me. Making me flash a windows 10 iso into my USB and try to install it again, only for it to show the error "Windows could not prepare the computer to boot into the next phase of installation". Sigh Jan 2, 2022 at 7:22
  • Don't use bootcamp past the first step. All you have to do is open bootcamp and DO NOT click 'continue' instead in the menu bar, click "Action" and there is the option to download only the required files. Also you can't use bootcamp at all past this one step. You will have to use the terminal. Jan 2, 2022 at 8:31
  • JordanDavid: You wouldn't happen to know if Windows 10 should be installed to BIOS or UEFI boot? Jan 2, 2022 at 15:53
  • It depends, but unless your PC is very old it can use UEFI, but Windows usually requires an MBR boot scheme for older versions. Jan 8, 2022 at 12:36

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .