Installing Windows

[JKent]

A little background: My late 2015 1TB "fusion" drive is apparently failure-prone so I abandoned it and transferred everything to an external SSD. Works fine. So I formatted the internal drives (the fusion shows up as 2 drives) with MS-DOS (FAT). Tried running Boot Camp Assistant and it apparently will only run on the internal drive and it told me I had to revert to fusion (?). So I re-reformatted one of the 2 to APFS. So now if I open Disc Utility it shows the Internal drives as "Apple SSD AP0032H Media" 24 GB. Under that is "Container Disk6" APFS Container and under that is I HD APFS Volume, 23.69 GB. Then the other internal drive shows up as "Apple HHD ST1000DM003 M..." and under that is "IHD 2" Formatted MS-DOS (FAT32)., 999.99 GB.

SO: I ran Boot Camp Assistant again and got the message "External storage device attached" "Please remove any external storage device attached to this system before continuing". I have 2 external drives. Now I can remove my external drive that is used for Time Machine but the other external drive is the 1TB SSD that is my boot drive and contains everything. Can't remove it or there will be no OS.

Is there any way to use my internal, failure-prone fusion drive as a Windows machine? It will be for playing games so I don't care that it will eventually fail.

Alternatively, could I get yet another external drive and use that as the Windows machine? It seems Boot Camp Assistant will ONLY run on the internal drive AND it won't allow an external drive during installation.

Thanks for any advice.

 

[Cory Cooper]

Hello.

• Which exact model is the iMac: iMac (21.5-inch, Late 2015), iMac (Retina 4K, 21.5-inch, Late 2015), or iMac (Retina 5K, 27-inch, Late 2015)?
• Which version of macOS?
• Which brand/model is the external SSD?

Boot Camp only works on an internal drive...it cannot be setup on an external drive. The only way to install Windows on an external drive running macOS is via Parallels or VMware Fusion.

Honestly, a 2015 iMac is probably too old to use as a Windows gaming computer, due to the system requirements of many current Windows games.

Hope that helps.

C

 

[JKent]

Hey Cory

Thanks for the help. It's an iMac Retina 5K, 27 inch, late 2015. Running OS 12.1. External SSD is Samsung T7 Portable SSD 1TB. I also have a Seagate external hard drive (not SSD) used only for Time Machine.

To be clear:

1. The Mac's internal fusion drive has been abandoned. The Mac is running off the external SSD and it has been working fine.
2. I don't want to set up Windows on an external drive. I was looking for a way to use the original, internal fusion drive. I was told the drive is on borrowed time but that's OK.
3. I have some old games from before I bought the Mac, and thought I could waste some time playing them.

So here's another thought (keep in mind that although I used to understand DOS and Windows pretty well I am a total noob when it comes to Macs). Could I install a version of the MacOS--maybe a slightly older one so it's clear it's not my "real" computer--on the internal SSD part of the fusion drive and run Boot Camp from there? I could use the entire spinning disk part of the fusion drive for Windows. Does that make sense? Right now the SSD part of the internal drive is APFS. The spinning disk part is formatted with FAT32.

AND--most importantly--could I even run Boot Camp on the internal drive while I have the Samsung external SSD connected? Remember--the Samsung drive is what runs the computer. The internal drive is "extra".

Thanks again
K

 

[Cory Cooper]

OK, thanks.

You could install an older version on the internal Fusion Drive and then use Boot Camp with Windows. That won't affect the external SSD - you would just use the Startup Manager to startup from the one you want to use. Your iMac will run a minimum of OS X 10.11 El Capitan. You would need to create a bootable installer for the older version of OS X, as it won't let you install it on another drive when started up from a newer version on your external SSD.

Sounds like the Fusion drive may have been split? I don't have much experience with the Fusion Drives other than how they came from Apple. I believe you can use them separately, as I remember seeing Internet articles on other sites about how to split them and recreate the Fusion Drive using Terminal.

C

 

[JKent]

Thanks Cory! I'll do an internet search on how to create a bootable installer and how to recreate a fusion drive. Assuming all goes well I'll report back here.
K