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Boot Camp error: An error occurred while copying the Windows installation files

Continued Conversation from Boot Camp error: An error occurred while copying the Windows installation files

I ran into this issue trying to install the full version of Windows 10 Pro October 2018 using 10.13.1 Mojave. I’m installing on a MacBook Pro 15 (2016).

I verified the system was fully ready to install. However this error occurred over and over. Finally I decided to push through manually and it worked. The problem is under the Windows 10 ISO under the Sources folder, there is a file called install.wim. This single file is over 4GB and can’t be written to a FAT 32 partition that Boot Camp creates. This is a limitation for FAT 32. Here was how I worked around it.

1. Star Boot Camp like normal.

2. Go to the point of failure where you get the error message.

3. Boot Camp will attempt to roll back the parition, but close Boot Camp so those two new partitions are kept. They are named OSXRESERVED and BOOT CAMP.

4. Use Disk Utility to erase the newly created “OSXRESERVED” partition, and with the erase feature, choose the ExFAT Format. (This format will allow you to write larger files than the FAT 32 format)

5. Manually copy all the contents from the Windows 10 ISO to the OSXRESROUCES volume.

6. Restart your Mac and enter into the boot selector (hold option key while restarting).

7. You’ll see an option called “Windows” to boot from. This is the installer.

8. As you go through the Windows installer, make sure to reformat the “Boot Camp” partition using the installer tool (this is step #4 from this help article Install Windows on your Mac with Boot Camp - Apple Support)

9. For the rest of the process follow step #5 from the above article. You’ll be clicking on the link “install Windows support software manually” (here is the direct link here If Windows Support Software isn't installed after you run Boot Camp Assistant - Apple Support)

I hope this helps! I’m staring at my window screen right now so I’m sure this setup worked for me.

Cheers!

MacBook Pro (15-inch, Late 2016), macOS Mojave (10.14.1), null

Posted on Nov 15, 2018 4:12 PM

Top-ranking reply

MrBoffo

Level 1

4 points

Posted on Feb 3, 2019 9:19 AM

While I'm not the author of the original post, I know what step 5 is. I believe there is a typo there, and that it should read "5. Manually copy all the contents from the Windows 10 ISO to the OSXRESERVED volume." After step 4 you should see a volume named OSXRESERVED on your desktop. Open the Windows 10 ISO. Copy the contents therein into OSXRESERVED. Go on to step 6.

To be honest, I tried this approach, and it didn't quite work. In the end I was able to install bootcamp using the standard installation process simply by using the older version of the Windows 10 ISO from Microsoft. (I think from October 2018?). That ISO does not contain the overly large file that necessitated the ExFAT technique outlined in evan-13's excellent post.

Hopefully Apple will update Boot Camp Assistant to work properly with the newest Microsoft ISO's.

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42 replies

drcjones

Level 1

4 points

Jan 18, 2019 3:35 PM in response to evan-13

Thank you for this work around!

It seems like this might be a slightly simpler solution:

https://apple.stackexchange.com/a/341760/317914

Using the software from twocanoes to create an iso with smaller files on it.

Jan 26, 2019 5:38 AM in response to evan-13

after the error of copying the Windows files, I get two partitions. The 2 partitions named: BOOT CAMP and disk0s3. I can't erase the newly created "disk0s3"to an ExFAT format. So I can't do this steps after step 2. can anyone help me?

Feb 16, 2019 8:17 AM in response to evan-13

Well, i figured an easy way to no avail in installing Windows 10 on the internal hard drive with the Copying windows installation error. Copy windows support software to exfat usb drive. Choose the windows iso of your liking and open it and manually copy files to the usb. Then run bootcamp and you will get the "Failed to copy windows installation". Exit bootcamp and go to disk utlity and erase the bootcamp partition and change the format to macos extended journal. Then restart MAC and hold alt key and choose windows drive. Installation will go thru and then you will come to choosing the correct drive screen. Delete the partition for bootcamp and WALA you are in business. This video is complementing partial content that i wrote.

Loner T

Level 9

59,536 points

Nov 16, 2018 4:06 AM in response to evan-13

The install.wim can be larger than 4GB if there are multiple Windows 'products' in the file.

Nov 16, 2018 11:19 AM in response to Loner T

The instal.wim is the problem file been trying different methods all day.

the method mentioned by even-13 works but if you want it easy then install the 1803 version

Nov 16, 2018 11:21 AM in response to evan-13

thanks for that I tried it on iMac 27 it works but wouldn’t recommend it for every one unless they have some technical knowledge.

Loner T

Level 9

59,536 points

Nov 17, 2018 6:47 PM in response to martincapal

What happens if you re-install Windows using W10 1803 and then upgrade to W10 1809?

Nov 18, 2018 1:51 AM in response to martincapal

As well as getting apple pre release software I am also a windows insider and from a lot of the feed back I read 1809 has A lot of bugs. Unless you really want to have the latest stick to 1803.

1slammer

Level 1

4 points

Dec 22, 2018 6:55 PM in response to 1slammer

Total time building new pc...4 hours.

Total time trying to get Windows installed...12 and counting

dong129

Level 1

4 points

Dec 22, 2018 8:28 PM in response to evan-13

From 5) How do you “manually copy all the contents from the windows to the ISO OSX? Can you be more specific?

Loner T

Level 9

59,536 points

Dec 22, 2018 8:37 PM in response to dong129

From 5) How do you “manually copy all the contents from the windows to the ISO OSX? Can you be more specific?

Can you upgrade to the latest Mojave and retry, without using any manual steps?

Dec 26, 2018 7:23 PM in response to evan-13

That link: https://twocanoes.com/using-larger-windows-10-isos-with-boot-camp-assistant/

worked after hours of me trying things on my own. Recommended!

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Boot Camp error: An error occurred while copying the Windows installation files