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

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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

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Answer 1

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MrBoffo

Level 1

4 points

Feb 3, 2019 9:19 AM in response to Loner T

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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Answer 2

Jan 17, 2019 12:22 PM in response to Mroksalmarer513

After updating my Mac OS to 10.14.2 it worked. I neglected someone's post where they mentioned this because I thought my Mac was up-to-date, but lo and behold that minor update does fix the issue I had.

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Answer 3

Loner T

Level 9

59,536 points

Feb 3, 2019 10:00 AM in response to MrBoffo

W10 1803 (April) has a smaller-than-4GB install.wim.

W10 1809 (October) has a larger-than-4GB install.wim.

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Answer 4

evan-13 Author

Level 1

15 points

Nov 15, 2018 4:35 PM in response to evan-13

Continued...

In place of step #9 you can download the Windows Support Drivers by booting back into Boot Camp Assistant and going to the Action drop down menu. Then choose “Download Windows Support Software.” You’ll want to first format a USB Thumb Drive as ExFAT and then save the file directly to this thumb drive.

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Answer 5

Loner T

Level 9

59,536 points

Jan 7, 2019 5:16 PM in response to D4close

I’m not sure how to do step 5? How do you manually copy the content from the Window ISO to the volume of the OSX?

Mount the ISO in Finder, select all files from the ISO main folder and copy to the USB.

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Answer 6

Nov 17, 2018 6:34 PM in response to evan-13

So after 8 hours(half a day) I managed to find a solution for my problem. Microsoft just released an installation iso file where the size of some files do not respect FAT32 limitations thus making BootCamp totally unusable.

This manual worked for me just fine.

HOWEVER, I am getting a REALLY REALLY bad sound quality in Windows 10. I have Cirrus Logic 4208 (or what) sound card and the sound is SOOOO bad. I even tried to connect my AirPods and they do not reproduce a good sound either(like the sound transfer is laggy).

Thank you for your manual. Now I have to try to fix my sound issues.
(my MBP is mid 2015 with dGPU)

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Answer 7

Jan 9, 2019 10:01 AM in response to evan-13

I made it to step 4 before experiencing complications. I tried to manually copy all the contents from the Windows 10 ISO, but when I click on the disk image of the Window ISO I get a message saying "The following disk images couldn't be opened" and the reason given is "Resource busy".

Did you mean to say copy the Windows ISO itself? Because at the moment there are no contents for me to manually copy, because it's an unpacked disk image... I hope you'll reply because after making it to step 4 and this happened I don't know how to proceed.

This ISO is on my desktop btw. I saw in a video that on the new Macs you can't do it without having to use a flash drive.

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Answer 8

Jan 10, 2019 1:20 AM in response to evan-13

So I've been trying to install the downloadable Windows ISO to my 2016 MBP since yesterday. I've done it in the past, but for some reason I'm encountering many obstacles this time.

The first problem was getting an error message after the Bootcamp partition didn't work: "An error occurred while copying the Windows installation files".

I followed the steps found in this here thread. I had to restart an extra time in order to unpack the Windows ISO to reach the content.

After some hiccups I finally made it to the point where I boot up holding the option key and click on the Windows OS.

I was brought to the install screen (for which I had to plug an external mouse in, thank god I have one), and I selected custom, 64-bit Home etc.

I followed step #8 and selected the Bootcamp partition to install to but received this error:

"Windows cannot be installed to this hard disk space. Windows must be installed to a partition formatted as NTFS".

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Answer 9

Loner T

Level 9

59,536 points

Feb 16, 2019 7:52 AM in response to rajamania

I dont understand what you mean. I am having the copying windows installation files in bootcamp error. Irregardless of what version of windows iso im using.

If the issue is related to copying files to OSXRESERVED partition on your 2017 iMac's internal drive using W10 1803 or older, you may have other issues related to the internal storage. I suggest you start a new discussion, because it is unrelated to W10 1803 vs 1809 ISO.

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