Level 1

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No sound on 27 inch iMac Mid 2011 running Windows 8.1 on Botcamp

Hello! I just installed 8.1 on my Mac and everything went very well. Then only issue I found is the sound and the brightness. I try to turn down the brightness but nothing happens. The bar shows that it's going down but it isn't. The sound is also broken. When I try to turn up the sound, there is a circle with a cross with the volume icon. I tried many things to fix the sound issue. I tried downloading new drivers, updating drivers, etc. The brightness issue, I don't really care but it would be useful if we can fix it too. I talked to Microsoft about the sound problem and they said the only way to fix it is to get Windows 10. Unfortunately, my mid 2011 Mac does not support Windows 10 on boot camp. I'm in desperate need of the sound in windows so I need your help! Thanks!

Posted on Oct 15, 2017 8:28 PM

Top-ranking reply

Loner T

Level 9

59,536 points

Posted on Oct 16, 2017 5:46 PM

Does your built-in Optical drive function properly?

amytom12 wrote:

And oh, I forgot to mention. When I was installing Windows 8.1, I got a MBR table error and something about EFI's and GPT. I looked on YouTube and this guy said to go to terminal on my mac side and put some codes in. I don't know if this effects the sound.

Yes, it does. If you do not use the internal Optical drive and a DVD (or CD) to install Windows on your specific model and instead use a USB (or manually choose) EFI boot, the Audio devices are not exposed correctly. This is indicated by the current BIOS Mode being UEFI. On your specific 2011 model, it should be Legacy (or BIOS).

The only method to switch to BIOS mode, is to remove the current installation using Remove Windows from your Mac - Apple Support and then use a DVD in the Optical drive to install W8.1. The 'code' you were asked to input in Terminal removed the MBR, forcing a UEFI installation, and causing the Audio to malfunction.

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152 replies

amytom12 Author

Level 1

12 points

Oct 16, 2017 10:16 AM in response to Loner T

So are you saying to boot into BIOS? How do I do that? And also, what happens if it is UEFI? If it is, does it mean I have to live without the sound?

amytom12 Author

Level 1

12 points

Oct 16, 2017 1:59 PM in response to Loner T

Hello. I just did msinfo32 and this is what I got.

So it's UEFI, how do I change it to BIOS? Do I have to reinstall Windows 8.1? And how to you install 8.1 into a BIOS?

amytom12 Author

Level 1

12 points

Oct 17, 2017 5:22 AM in response to Loner T

And yes, my optical-drive works. Isn't that the CD slot on the side of my mac?

amytom12 Author

Level 1

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Oct 17, 2017 10:00 AM in response to Loner T

Okay, what do I do after that? Do I install windows just like installing it on a USB but it's a disk?

amytom12 Author

Level 1

12 points

Oct 17, 2017 10:19 AM in response to Loner T

Do you know if anyone has a YouTube video that shows you how to install with a DVD? I'm only used to download it on a USB drive.

amytom12 Author

Level 1

12 points

Oct 17, 2017 12:56 PM in response to Loner T

Hello! I just searched through my DVD pile and found 2 DVD types : DVD + R DL and DVD - R. Will these work? I don't have any DVD-R SL's though.

amytom12 Author

Level 1

12 points

Oct 17, 2017 2:48 PM in response to Loner T

Okay, i'll get those drivers. But i'm running into an issue.

It's saying that even though I have my DVD + R DL in my optical drive.

Loner T

Level 9

59,536 points

Oct 17, 2017 2:57 PM in response to amytom12

From a Terminal Window, with the DVD in the drive, post the output of

diskutil list

amytom12 Author

Level 1

12 points

Oct 22, 2017 6:13 AM in response to Loner T

Hello! I have a question. Does it have to and at least 4.75 GB or can it be 4.7? My store only sells 4.7 and 8.5. 8.5 is too expensive and there is no 4.75 DVD's.

Loner T

Level 9

59,536 points

Oct 22, 2017 6:25 AM in response to amytom12

The ~4.7Gb disk will work. The 8.5Gb are not worth the money for this purpose.

amytom12 Author

Level 1

12 points

Oct 22, 2017 7:23 AM in response to Loner T

Okay. Thank you for the information!

amytom12 Author

Level 1

12 points

Oct 24, 2017 12:50 PM in response to Loner T

Hello. Do I have to use a DVD - R or can I just use a DVD + R? - R's here are more expensive than + R's. I was thinking if we could use + R rather than -R. Thanks!

Loner T

Level 9

59,536 points

Oct 24, 2017 1:43 PM in response to amytom12

Either one will work, as long as your are able to burn it successfully. Please also see Re: BootCamp "Installer disc could not be found", with ISO DVD.

amytom12 Author

Level 1

12 points

Oct 25, 2017 12:57 PM in response to Loner T

Ok, thanks for the information!

amytom12 Author

Level 1

12 points

Nov 12, 2017 10:49 AM in response to Loner T

Hello. So I just burned the ISO to the DVD + R. So now do I just open BCA and uncheck all the other boxes besides the "Install Windows 7 or 8 " box?

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No sound on 27 inch iMac Mid 2011 running Windows 8.1 on Botcamp