How to use Bootcamp to run Windows 10 Preview on OS X Yosemite

Published November 27, 2014

I've been playing with Windows 10 on VirtualBox for a while , but the performance on my 2013 13" MacBook Pro Retina is a bit lacking. Since I'd like to get back into playing a few games on this MBP, I decided to take the plunge and install Windows 10 on Bootcamp. I couldn't find any good guides online, so here's a blog post describing in detail what I had to do to get it working.

What you need:

  1. Relatively recent MacBook Pro or similar
  2. A good backup in case you screw this up
  3. A 4 GB USB flash drive or larger
  4. Patience -- this took about 90 minutes (excluding ISO download time, which was about 3 hours on my old cable modem that I need to replace)

1. Download Windows 10 Preview

Go here: http://windows.microsoft.com/en-us/windows/preview-iso

...and follow the instructions to download the ISO. I chose the English (United States) 64-bit (x64) version.

You can continue on while it's downloading. It's 3.8 GB.

2. Clean out your USB drive

Since this process will result in wiping your USB flash drive, make sure you've copied all the info off of there that you don't want to lose. Keep it plugged into your Mac.

Note: I also formatted the drive as exFAT just in case. I'm not sure if this step is necessary or not.

3. Launch Boot Camp Assistant

Boot Camp Assistant

4. Choose Windows 7 or later

Check both of the active boxes (the middle one should be checked but grayed out).

Select Tasks

5. Select the ISO image

When your download is finished, select it in the next box.

Open ISO file dialog

6. Make the install USB flash drive

Allow Boot Camp Assistant to wipe your USB flash drive and it'll copy Windows onto it.

copying windows files

It'll also download more stuff. This took about 10 minutes for me.

7. Create a partition at least 25 GB

Boot Camp Assistant will ask you how much room to add for Windows 10. I'd recommend at least 25 GB. Since I plan to play games on it, I chose 60 GB.

By the way, a good way to free up hard drive space on your MacBook Pro is to move larger files onto a USB drive. I found a 128 GB USB drive with great ratings for $35 which is pretty nuts. That's the size of my old MacBook Air's entire hard drive...here's the link.

While partitioning the drive, I got this error:

The disk cannot be partitioned because some files cannot be moved.

Back up the disk and use Disk Utility to format it as a single Mac OS Extended (Journaled) volume. Restore your information to the disk and try using Boot Camp Assistant again.

The disk cannot be partitioned because some files cannot be moved

This will save you a lot of time, so let me put it in unnecessarily loud bolded text:If you follow these steps properly it should NOT require you to reinstall or clone/restore like this recommends.

I got around this by going to Disk Utilities in Recovery mode and repairing the partition.

First, restart in recovery mode by holding Cmd+R while booting up. Select Disk Utilities and do a repair on your main HD partition (NOT the first option in the volume list, usually the second).

disk utilities

Note that you might have to unlock your hard drive to get to the partition Repair Disk. It's on the top toolbar (not pictured above, but you'll see an Unlock icon).

Once the repair is done, restart your Mac normally, log in, and start Boot Camp Assistant again. This time, skip the install disk and download checkboxes.

select tasks

It will partition properly this time. Whew!

8. Install Windows 10

This is a pretty simple process. Boot Camp Assistant will walk you through the process.

It takes a long time, though, like 20 minutes at least I think. Have something else to do in the meantime.

9. There is no step 9

I've always wanted to write that.

WINDOWS running on MAC that's insane

Hit me up on Twitter if this helped you! Feel free to let me know any refinements needed. I probably won't be able to provide any tech support though, so figure it out on your own. :)

Happy Thanksgiving!

Update 12/7/2014

A few notes after using this for a while:

  1. Make sure you have enough space. 60 GB wasn't nearly enough and I had to blow everything away and reinstall, running intothis problemin the meantime.
  2. Make sure you install all the Boot Camp drivers on the Windows side, or bluetooth and WiFi won't work.
  3. If you're running OS X Yosemite, your hard drive has likely been formatted using Core Storage rather than HFS+. Because of that, Windows won't be able to access anything on the Mac side, nor are there any third party tools that I've found that allow that. Supposedly you can switch back to HFS+, but I wouldn't recommend that. Bummer. Best way to transfer files is to format a flash drive as FAT (exFAT?) and move files that way, or use Dropbox.