iMac 21.5 late-2015 model boot camp driver support

From How to install Windows on your Mac with Boot Camp - Apple Support and the Learn More section says

Learn more

With OS X El Capitan 10.11 or later, these models use the internal drive to temporarily store what you need to install Windows, so you don't need a USB flash drive:

• MacBook Pro (2015 and later)
• MacBook Air (2015 and later)
• MacBook (2015 and later)
• iMac (2015 and later)
• Mac Pro (Late 2013)

You have a 3TB Fusion drive which has been partitioned for EFI. Legacy BIOS mode cannot address a disk larger than 2TB, due to MBR limitations.

Can you remove all external storage, remove Windows using BCA, run the following two resets,

Reset the System Management Controller (SMC) on your Mac - Apple Support

How to reset NVRAM on your Mac - Apple Support

put the ISO file on the internal macOS drive and re-run BCA and try a 'clean' install? BCA will download the correct drivers from Apple before it starts partitioning.

Do the internal speakers work correctly on the macOS side? Do you have any cables connected to the back of the iMac? If you look in the Audio connector, is there a faint red light visible?

Can you post a screen shot of Audio Input and Output Devices in Windows Device Manager? It should look similar to

This is W8.1 on an iMac5K. The first screen shot is before the BC drivers get installed. The second is after BC drivers are installed.

Can you try to manually install Cirrus drivers from the BC6 drivers package downloaded using BC Assistant?

I just ran Brigadier and that solved the problem. I was just about to send the new picture of device manager. I really appreciate all the time you spent helping me. It seemed pretty clear it was a driver problem-I just couldn't seem to get te right one installed Brigadier did the magic!

The BC Assistant will not download older versions. For W10, it will only download BC6 versions. BC6 drivers are not available via Apple Downloads. BC Assistant is the authoritative source for drivers. Brigadier is an option, but only if all else fails and requires the correct choice of Model and Product being made during the download.

The BC5 drivers are meant for W7 and are listed in Install Windows 7 and earlier on your Mac using Boot Camp - Apple Support . If possible, I suggest removing the current W10 installation, and starting over again.

Did this ever get resolved? I am fighting the same problem-no sound from internal speakers or from headphone output. The sound troubleshooter in Win 10 shows both devices as working, but no audio. The sad thing is that I had Win 10 working perfectly for over a year, but had to do a new Bootcamp installation and now can get no sound.

Your 2015 Mac should have an EFI installation of W10. You can confirm this by running msinfo32 and looking at BIOS mode, which should say 'UEFI'.

Can you check Device Manager and post the devices you see under Audio?

I had AMD High Definition Audio. I say had because in the process of trying to make sure I had the most up to date driver, something got corrupted and everything froze. I got so frustrated (been working at this about 6 hours) that I decided to just do a clean reinstall. Deleted the partition in Bootcamp Assistant only to find that the partitions didn't reassemble properly. Had to go into terminal to fix that and am just now reinstalling my iMac backup. I'm not sure I have the stamina to try this again, although I use a number of Windows programs regularly.

The internal speakers will use Cirrus or Realtek, while external audio connections can use AMD HD Audio. Disconnect all external storage, before you attempt to install Windows, otherwise you will see partitioning errors.

Thank you. I learned the hard way about partitioning errors. In my last attempt to get sound, I did reinstall both Cirrus and Realtek drivers-to no avail. What has me stumped is that when I did this a couple of years ago, everything worked fine. I'm wondering if using updated boot camp drivers from that original installation is causing the problem. Is it possible to load the drivers that I would have used then?

Well...that may be my problem, but I'm not sure why I got different versions. In each case, I used Bootcamp Assistant and the Windows Support Software downloaded as a part of the setup. I didn't select anything. I assumed the drivers were automatically installed during installation of Win 10. When the sound wouldn't work, I went to the Apple Support page which has all the driver packages listed and took the latest one displayed-believe that was the 5.1.5621. I then tried to reinstall the drivers manually to see if that made a difference. Honestly, I have no idea where the other two came from, but I suppose I may have downloaded another different package somehow. I've gone through the installation process so many times, I may have. So...if I run Bootcamp Assistant, how do I insure that the latest drivers are those downloaded, and do they get installed automatically?

I did a complete reinstall action using Boot Camp Assistant after eliminating any files which appeared to be associated with any earlier drivers. Result was the same-no sound. Looking at playback devices shows Digital Audio active when a YouTube video is played.

No. I had to wipe my drive, assemble the hard drive using Terminal from partitions which Bootcamp Assistant would not reassemble, reinstall my operating system (Sierra) and restore a Time Machine backup. I then used Bootcamp Assistant to repartition and reinstall from a Win 10 ISO that was on a USB 2.0 thumb drive. I had no other devices plugged into the computer.

Can you post the output of

diskutil list

from macOS Terminal?

The ISO should be on the internal disk, and can be freely obtained from Download Windows 10 Disc Image (ISO File) . The USB2.0 with the W10 ISO can cause issues.

Interesting that the use of the USB might be a problem since those are the specific instruction in the Apple Bootcamp installation instruction. Terminal output below:

Last login: Sun Aug 6 02:45:20 on console

DESKTOP-47QNSNL:~ HL$ diskutil list

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *3.0 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_CoreStorage Macintosh HD 2.5 TB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data 509.0 GB disk0s5

5: Windows Recovery 886.0 MB disk0s6

/dev/disk1 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *121.3 GB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_CoreStorage Macintosh HD 121.0 GB disk1s2

3: Apple_Boot Boot OS X 134.2 MB disk1s3

/dev/disk2 (internal, virtual):

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS MacintoshHD +2.6 TB disk2

Logical Volume on disk0s2, disk1s2

0EAF01F6-F97B-4027-852A-83C532D0E72A

Unencrypted Fusion Drive

/dev/disk3 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: FDisk_partition_scheme *31.0 GB disk3

1: Windows_NTFS BTCMP Setup 31.0 GB disk3s1

DESKTOP-47QNSNL:~ HL$