Anyone can do this and it is fun to have Windows running on your iMac, strange too! You don’t have to install windows 10, it can be 7 or 8 as well.
This was easier than expected. I tried this before on my 2010 iMac and ran into some trouble. This time it only took about 30-45 minutes (not including download times) and everything worked perfectly. This may not always be the case for you and this process partitions your hard drive and installs windows on it, so be careful. Backup anything important in case something goes wrong and you lose everything.
Also, you need an external 8GB+ USB hard drive or flash drive.
Ok here goes…
How to install Windows 10 onto the new iMac 5k:
First download Windows 10 Tech Preview here
(full page with more options is here http://windows.microsoft.com/en-us/windows/preview-iso)
This is the 64bit version that you will need for your 64bit iMac.
After you download the 3Gig file, open up disk utility on your iMac
It can be found in the Applications folder, inside Utilities.
Now find the ISO you downloaded, it should be in your downloads folder. Double click it.
The image mounts and a window pops up showing the contents of the DVD image.
Go back to the Disk Utility, you should see the ISO and under it DVD image loaded.
Highlight the ISO file and right click it. Then choose convert.
(In this step I am converting it to a CD/DVD master. For some reason i needed to do this or Bootcamp wouldn’t make my install disk.)
Now where you want to save the file, and pick image format: DVD/CD master. Then click save.
This will save a CDR file in the location you chose. (Choosing Desktop makes it easy to find again.)
Ok time to start using BootCamp. Click the little search magnifying glass at the top right.
Start typing Bootcamp and it will appear, double click it to start.
Make sure all 3 check boxes are ticked.
Create Windows 7 or later version install disk, Download the latest Windows support software from Apple, Install Windows.
Click continue. At this point you need an 8GB or higher USB, Flash ,Thumb, drive thingamagig. I used a 1TB backup disk.
Insert the drive, wait for it to load and choose the CDR file that you made as the source
Choose the USB drive you inserted as the destination
Click continue and wait a while, go get a snack or a drink.
It will install windows 10, then it downloads and installs drivers (windows support software).
FYI those drivers will be installed on the USB drive in a folder called Bootcamp, you will need to install them later.
Finally you get to choose how much space you want for Windows.
I chose 125 GB, but you can choose more. Just slide the little slider to the size you would like.
Click continue and wait for disk partition.
Wait longer and longer…..a looooooonnnngggg time later the computer restarts!
Windows starts to load woohoo!
Choose custom install (if this is the first time)
Choose the bootcamp partition, which is where you want windows installed.
Choose FORMAT!!! Yep you have to format it to the NTSF file system or Windows won’t install, but it won’t hurt anything. Bootcamp just erased it right before this. I don’t know why bootcamp doesn’t just format it with the NTFS file system since it helps you with everything else.
Don’t pick your main iMac hard drive installation accidentally. Formatting deletes everything and you can’t easily get it back.
Now wait again…
Wait for, copying windows files, installing stuff, etc…
After a while the computer mystically restarts itself again!
Then wait while it gets your devices ready, whatever that means.
Oh look…it restarts again… all by itself.
Finally this time you will see Windows 10 loading up
Create a user name and password, it actually wants you to use a Microsoft Live account, which you may have one if you own an Xbox.
Now Windows will load up completely and you are at the desktop! Congrats, you are almost done.
Let’s install the iMac drivers for all of the devices in your amazing 27inch Retina iMac 5k!
Go to my computer, click on your USB drive. Find the bootcamp directory and run Setup.exe
That will install all of the needed drivers for your computer.
The computer will blank out a few times and then asks you to restart it. Do that.
Once the computer restarts it will load windows and be fully operational!!!
Now use windows to your hearts content! And take a few pics with your phone showing Windows loaded on a computer with the Apple logo. People will start calling you a hacker in no time!
OK something else important. When you restart the computer it always loads up windows!!! How to get back to your MAC stuff…
Reset the computer
As soon as it makes the crazy loud loading sound while the screen is black still
Hold down the ALT/OPTION key on the key board
A menu will pop up eventually that allows you to pick your boot device
Choose the first Macintosh HD
Now the Mac OS X side of you hard drive will boot up.
Now inside of Mac OS X you can change which side loads up.
Go to settings, click Start Up Disk
In that menu you can choose which operating system that you want to always load up.
Either choose Bootcamp Windows for Windows to always load, or Macintosh HD to load the Mac OSX.
At anytime you can hold ALT OPTIONS during restart to override and choose a different one.
OK guys, I hope that helps a lot. I will try to get some type of video up about this and more screenshots on the Windows 10 side later.