Our scenario is we have Intel iMacs that were all configured to have Boot Camp/Windows partition.

Those that have basically never booted into Boot Camp are fully updated to latest Apple security and feature updates for MacOS.

Those that always boot directly to Windows of course do not.

We are trying to determine if it's reasonable or of any benefit to update the windows Macs to a new macOS.

Can Mac updates to a Mac listed as iMac: Apple Inc. 1731. SMBIOS 3.3 Date: 5/3/2022 do anything on the firmware side or other that will break Boot Camp and render that useless, or worse, brick the iMac?

  • 2
    Sources would be useful - especially as Mac doesn't have, & has never had, a BIOS.
    – Tetsujin
    Commented Oct 2, 2023 at 13:07
  • 1
    I'm going to edit in a bit of "exaggeration" into your question. If you could list a specific model or a specific build - that would help us narrow down. You're unlikely to get a good answer without some specific build of macOS even if not all your Macs are the same era / build / version.
    – bmike
    Commented Oct 2, 2023 at 13:15
  • I'm editing out " I searched" since that helps no one. If you can document exactly what term you used to search - what results you considered and why those results were not useful - then we can help.
    – bmike
    Commented Oct 2, 2023 at 13:16
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    It's not really. Anyone mentioning BIOS - which is a motherboard property, nothing to do with the CPU architecture - likely has the wrong end of the stick somewhere. Hence the request for references, so we can see if they're right or wrong. The point is probably moot now, as reference to those searches is now gone.
    – Tetsujin
    Commented Oct 2, 2023 at 13:24
  • 2
    That's a model identifier, it's not the same as a Windows-type BIOS. Macs are EFI boot, not BIOS boot. Anyway, i'm done arguing. Wish you luck.
    – Tetsujin
    Commented Oct 2, 2023 at 13:33

2 Answers 2


Intel Macs through the 2014 model year either were shipped with a BIOS in the firmware or a BIOS could be installed through a firmware update. Originally, firmware updates were manually downloaded and manually installed. The latest of these updates are documented in the Apple website About EFI and SMC firmware updates for Intel-based Mac computers. This website also states that all further firmware updates will be installed when you update or upgrade OS X/macOS. Starting in 2015, Apple starting shipping Macs without a BIOS. These Macs can only install an UEFI booting Windows.

There are no practical reasons for Apple to produce a firmware update that would disable or break a Windows installation done thought the use of the Boot Camp Assistant application. In fact, there was at least one instance, where due to a change made by Microsoft, Windows 10 could no longer be installed though the Boot Camp Assistant without first getting a firmware update from Apple.

So there exists the following possibility. You have Windows installed on a Mac and you find you need to reinstalled Windows, only to find you cannot unless you upgrade your version of OS X/macOS. In other words, you need to upgrade OS X/macOS to get the firmware update needed to continue using the Boot Camp Assistant to install the current Windows release.

  • Re "There are no practical reasons for Apple to produce a firmware update that would disable or break a Windows" - well no duh. But there are "whoops" reasons it can (and my case) did.
    – SKidd
    Commented Oct 3, 2023 at 15:51
  • "it can (and my case) did" details of this should be in your question, not tagged on as a late vague comment.
    – Tetsujin
    Commented Oct 4, 2023 at 10:09

First, as of 3 October 2023 this is the #1 result in Google for questions regarding BIOS and Boot Camp. Proves nothing other than it's a valid question as there are many other results basically about the same thing. Reddit and others have similar threads. The total (effectively) "you are dumb" early responses are a sad statement that speak for themselves.

Yes, there is no BIOS as such as there is on a win32 Intel Windows machine, but Windows still needs what it recognized as BIOS to run.

When the Mac EFI etc. gets updated, it can affect that part of the equation. What Windows gets from that boot may not work for whatever reasons.

And on this iMac, Windows returns BIOS information, "Apple Inc. 1731. SMBIOS 3.3".

So, that's basically it. As far as I am concerned, an update where the SMBIOS flakes out will brick Boot Camp. And if anyone can show how that is NOT possible or what is wrong with this, please feel free to pile on.

  • What did you search Google for? Can you add this to your question or answer in such a way the results can be reproduced? What Reddit threads are you referring to? Can you post links to such threads? I expect proof of claims to be backed up with something better than "Hey it's out there on the internet". Not all Macs need a BIOS to run Windows. Your statement to the contrary is false. Commented Oct 3, 2023 at 21:33
  • Please don't use the answer space for additional information. it should be edited into your original question. Stack Exchange is not a forum, it is a question & answer site.
    – Tetsujin
    Commented Oct 4, 2023 at 10:07
  • SKidd: You are claiming without any evidence or proof there is a problem. You have not even explained what the problem is. So far you have just been ranting. Now you have the audacity to ask us to show this undefined problem has never occurred, when you cannot even show one instance where the problem has occurred. Commented Oct 9, 2023 at 22:54

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