Successful Windows 10 Upgrade, 2011 iMac 27", Anyone Else?

I also have the same model and upgraded from Windows 7 to 10 without too many issues initially. I only had to reinstall the drivers for my keyboard to get the volume keys to work again. I was also pleased to find that my gpu drivers had been updated from 14.3 to 15.something – one week older than the 15.7.1 currently available. I was able to further update to 15.7.1 by manually updating the drivers by downloading the file then going to device manager -> display adapter -> update driver using files on computer.

However yesterday while using Edge – and later Chrome – to download some large files Windows kept crashing; I'm using Wifi to connect to the Internet. Files of 256MB were fine but 500MB resulted in IRQL_Unexpected_Value crash (not sure of where the exact cut off point is between the two file sizes). Up until then I didn't notice any internet issues as my Steam and Origin games updated themselves and I played online. Either everything was being broken down into smaller packets – which is likely – or something broke in the last few days. After spending several hours trying to figure out how to open and read the memory dump files from the crash it appeared to be an issue with the Qualcomm Atheros drivers which were still dated from 2010. I then spent several more hours trying to find official site for updates, but apparently Qualcomm can't be bothered with that. I had to finally settle on https://www.atheros.cz/ as my source of drivers for the AR938x and updated to version 10.0.0.308. As of now downloading large files appears to work.

I'd be interested to know if anyone else has run into the same issue.

I also ran into the same BSOD problem when I tried to do a clean install of Win10 earlier this year on my mid 2011 iMac.

I tried it several times and it always crash either at the very end of the install or on the first 60 seconds after the initial boot after the install finished, after several attempts using safe mode I managed to sort of get windows 10 working without crashing but there was a bunch of essential programs and settings missing from windows so that ended up being a useless install and after I just gave up but I would love to get Win10 working on this machine, I hate macOS, performance has been terrible these last couple of years.

I too have a 27-inch, Mid 2011 iMac. I upgraded from Windows 7 to Windows 10 two days ago without any issues... until I realized Boot Camp didn't work (haha silly me). Just today I reverted back to W7, am currently downloading Yosemiteas an upgrade from Mavericks, and I will attempt to re-install W10 once everything is in place with Boot Camp.

As for my short experience with W10, well, it was actually quite enjoyable. I have an Xbox One so the new interface in W10 was an easy transition for me - a lot of the apps and tools are similar. I even fired up the Xbox app and was able to stream my Xbox One to my iMac from the living room and play some Destiny. Really cool stuff.

Can't wait till all of this downloading and re-installing is complete. I'll update soon.

Edit: as a note, I have upgraded the RAM on my system to 32GB. Its the only physical modification I've done.

I have the exact same model as you and have had no issues with windows 10. Even though it is not supported officially because bootcamp 6 only goes back to 2012 models. I did an upgrade from windows 7 as well to avoid any unforeseen issues, I'm currently only using 16 GB of ram because I don't see a need for 32.

Zippy, what version of Boot Camp are you running? Before I installed Yosemite I was getting crashes in W10 while trying to switch back to OSX so I'm hesitant to try the W10 install without Boot Camp 6. Are you using version 5 still? Is it even possible to install version 6 on a pre-2012 Mac?

I'm still using 5.1 with no issues, and to answer your other question, no it isn't possible to install bootcamp 6 on a pre 2012 imac unless apple changes it. the best advice I can give is to open bootcamp assistant in osx and check the box to download the latest support software onto a flash drive then install them on windows.

Same, I have a iMac 27" (mid 2011, 3,4Ghz, 16Mo) with a Win7 partition, I upgraded it to Win10 : no problem till I noticed that i have no more sound !

Everything look OK , but no sound at all.

I tried to install Boot Camp 6 to obtain the last sound drivers, but impossible to download it.

So Win10 ok -but without sound till now.

I ll try to download sound drivers directly from website.

WFauchey, download the latest drivers while booted in W10. Worked for me - keyboard and audio were previously not working.

I also have a 27" 2011 iMac (i7 860 @ 2.8 GHz, 16 GB RAM) but am currently dual-booting with Windows 8.1 and El Capitan beta. I thought 8.1 was required to upgrade to Windows 10? I am happy to see that you all did not have any problems, as I am about to do the upgrade as well. I was a bit worried that it wouldn't work since Boot Camp support seems to have been dropped for us 😠. I hope to continue to use this as my "super machine" for the foreseeable future. I also use it as a television with my DirecTV reciever, PS3, and PS4 due to lucking out that it is able to accept incoming signal in its DVI port. I would be very sad when the day comes that something major is not supported on this... Will update post after installation - wish me luck!

One question though, how are you all downloading "the latest boot camp drivers" if they are officially unsupported?

Unless you have an Apple supported computer besides your 2011 iMac, there is no way to get Boot Camp 6 as far as I can tell. Even if you could get Boot Camp 6, there is no guarantee that it will have drivers for all the components in the 2011 iMac it may have some but certainly not all, which is why the 2011 iMac isn't supported by Apple.

The best you can do is use Boot Camp 5.1.5621. Most of the drivers will carry forward during the upgrade process from windows 7 or 8 to 10. The keyboard driver definitely needs to be reinstalled from Boot Camp 5.1 based on all the complaints I've read – the driver works but for some reason gets lost during the upgrade process.

So I'm guessing that it is all done on the OS X side of things? I am not finding a way to update Bootcamp on the Windows side for some reason. (Surprising, since I was prompted to install the iCloud for Windows Beta v5...😕)

One more question - how long did it take from when you all requested the Win10 update to when it became available to you? Or, did everyone here do a clean install? I didn't realize there was a wait until now... I only use Windows a little bit of the time so I can't sit around with Windows up all day for that reason only.

Thanks for the help!

Where can I find Boot Camp 5.1.5621 ? I can't use the classic install (app store) because I already downloaded and installed it (and the Windows side of BootCamp wasn't use it during the Win10 install process). Or where can i download the win10driver for sound card, keyboard (I found the video drivers from AMD.com).

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I did an upgrade from Win7 (and not a clean install , because of the problem of licence's key). I 'll do the clean install in the future FROM the update version. Because now my Win10 is validated.

I took me about one hour for the Win7 home Premium version, with an optical fiber (~400Mb/s Download).

My iMac is a mid2011 27" I7 3.4 Ghz with 16GoRAM.

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Perhaps it's just because it's new but i have the feeling that it is much faster than the Win7.

I'm running windows 8.1 pro on a mid 2011 i7 3.4ghz with 24gigs of ram and tried to upgrade to 10 a few days ago. Installation seemed to be going smoothly, however after a few installation restarts, I got a black screen. I had to force reboot it and thankfully the installation was undone. So now I'm trying to figure out how others were able to successfully upgrade their windows on older mac models.

How did you install your windows10?

Personnaly I simply used Windows10 Install Tool link here : http://www.microsoft.com/en-us/software-download/windows10

I downloaded the 64bits version and launched it from Win7 part of my iMac (not by boot camp).

I choose the option "Update this PC now" and NOT "Create a new installation media".

I choose not to stay with my old docs and apps (previously saved).

After the big download if choose english. And after few reboot it was done.