iMac (not sure exact model yet) unable to boot to OSx from Windows (bootcamp)

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Figured I'd get this question out and rolling before the machine landed here at my shop.

Have a customer who is having issues booting back to their OSx from Windows, essentially even when they choose the option to restart in Mac OS they are redirected back to Windows when the iMac restarts.
They had had the issue about a month or so ago and I found the issue was due to SIP being enabled and preventing the Windows partition from making the change to boot to the MacOS.
I walked them through over the phone to see if SIP was still disabled and according to Terminal it still is.

So what else could be preventing them from boot to the MacOS?
 

chscag

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Enabling or disabling SIP should have no impact on whether or not your customer can boot back to macOS from Windows. Without knowing what version of macOS they're running or the version of Windows, it's difficult to diagnose what could be wrong.

The first thing is have them do a PRAM reset. Then if the machine still boots to Windows, have them open the Windows control panel boot camp app and select to boot to macOS from there. Or, they can use the Windows boot camp Tray option to select macOS. If the macOS EFI partition has been overwritten, then the only choice left is to erase the hard drive and start over. Which means they'll need to install macOS and Windows again if they still want to use it.
 
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They'll hopefully bring the imac in sometime today. Off the top of my head (and this was probably 40 computers or so ago for me) I'm fairly certain it was running Mojave.
Can't seem to find the page at the moment that I had come across that pointed the finger at SIP being the problem, but if I do I will post it.
 
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Here's the info on the imac, its a 21.5" late 2012 model. Currently running macOS Mojave 10.14.1, Windows side is 7 Pro.
So here is what I'm seeing so far:
Windows- clicking on boot camp and selecting "restart in OS X" results in restarting back into Windows. Opening the Boot Camp Control panel, the Windows BootCamp partition is the only visible there. Should the OS X also be visible here?
OSx- Did the PRAM reset, got back into macOS without having to interfere with the boot.
Ran the disk repair on the mac partition for good measure, doesn't look like it found any issues. Restarted back into OSx ok.

Checked with the customer on how they were transitioning from the macOS to the Windows partition. His method from going into Windows is to choose it as the start up disk. Not sure this is the best method, to me it sounds like the Windows partition is being locked into being the default startup partition by the Mac OS.
 
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In macOS, go into System Preferences > Startup Disk, and confirm that the Mojave partition is selected as the startup disk, then restart.
 

chscag

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Might have found the root of my issue, though I maybe wrong. I found some info that describes BootCamp having issues reading APFS partitions and that maybe why the OSx doesn't appear as an option in the Control Panel for Bootcamp.
Has anyone used the rEFInd Boot Manager before? This is the link I'm looking at: https://apple.stackexchange.com/que...ed-after-installing-windows-10-using-bootcamp

Since the PRAM reset got it back to macOS, you're probably on to something about APFS partitions not being seen. There are numerous threads in the MacRumors forum about using Boot Camp with Windows 10 and Mojave. There are work arounds which seem to work.

I would avoid using the rEFInd Boot Manager with Mojave and APFS. Reports are that it doesn't work.

You might want to advise your customer to resort to using Parallels or VMWare Fusion if he/she needs to run Windows programs from their Mac. Both work well for most Windows programs. The exception being running graphic intense games.
 
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Would there be much of a difference between "Windows 10 and Mojave" vs "Windows 7 and Mojave"?
 

chscag

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The Mac you're referring to (Late 2012 21.5" iMac) is able to run Windows 7 64 bit using Boot Camp 5 and Windows 10 64 bit with the latest version of Boot Camp. Keep in mind, however, that Mojave converts the hard drive format to APFS which may cause difficulty.
 
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chscag are there any particular posts you can link me to that state a fix? There's a metric butt tonne for APFS and Bootcamp but alot of them aren't applicable to my situation, I'm going to see if I can find out in the meantime.
 

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The Boot Camp and Windows discussion forum at MacRumors should help you find a fix. Follow this LINK.
 

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