Home / an error occurred while copying the windows installation files. An error occurred while copying the windows installation files. 01/04/2021 NOTE: THIS UTILITY SHOULD NO LONGER BE NEEDED DUE TO APPLE UPDATING BOOT CAMP ASSISTANT TO USE EXFAT. WE HAVE LEFT THIS ARTICLE AND THE DOWNLOADVERTISEMENT FOR HISTORICAL PURPOSES. IT IS NO LONGER SUPPORTED.You watching: An error occurred while copying the windows installation files.In the last few months, world installing Windows on their Macs with Boot Camp Assistant have actually began seeing the message “An Error developed while copying the Windows installation files” once utilizing some Windows 10 ISO downloaded from Microsoft. I have checked out it a lot, given that I perform experimentation with ISO of Windows Enterpincrease downloaded from Microsoft that have actually been mirroring this trouble. It didn’t seem to happen through all ISO so I investigated the issue, filed an insect through Apple, and determined a workabout to the difficulty.The CauseWhen Windows 10 is installed via Boot Camp Assistant, Boot Camp Assistant prepares the disk for installation. To perform this, it does the adhering to operations:Downfill the Windows Support software program from Apple for the present Mac.Creates 2 partitions, one wbelow Windows will be set up (“BOOTCAMP”) and one wbelow the installer documents will certainly reside (“OSXRESERVED”). Both are formatted as FAT32.Copies all the papers from the ISO that was mentioned at the start of the process by the user to the OSXRESERVED partition. This is wright here the error happens.Copies the records from the WindowsSupport to the OSXRESERVED partition. These documents carry out both the motorists needed as soon as installing and also the motorists that are set up post-install.Sets the boot disk to the OSXRESERVED partition and reboots.Windows boots from the OSXRESERVED and mirrors the obtainable editions of Windows from the install.wim file in the assistance folder on OSXRESERVED. This is a huge file (usually approximately 4 GB). The install.wim contains all of the documents for a vanilla copy of Windows 10 and also is the biggest file in the installer ISO.See more: My Copy And Paste Not Working In Chrome ? Why Doesn'T RightSo, here is wright here the difficulty resides: FAT32 cannot take care of papers better than 4 GB. Each new variation of Windows increases the size of this file, and also ISOs that contain even more editions of Windows can be larger than various other ISOs that contain less editions.In action 3 above, the error message “An Error emerged while copying the Windows installation files” is shown because Boot Camp assistant cannot copy the install.wim to a FAT32 filemechanism. This file is forced, so the whole procedure aborts.To make matters even worse, the disk in the Mac is left in a state wright here it is difficult to revert earlier to a solitary partition. The OSXRESERVED partition is hidden and unmounted, and Boot Camp Assistant cannot gain back a disk that has actually multiple FAT32 partitions.The SolutionTo deal with this problem, both FAT32 partitions should be removed from the disk and also a new ISO need to be produced wright here no single file is larger than 4GB. We have actually produced a cost-free energy called “Boot Camp ISO Converter” that copies all the documents in the ISO to a folder, splits up the install.wim right into parts no larger than 2GB, and also creates a new ISO that can be supplied with Boot Camp Assistant. Here is a step-by-action instructions:Rerelocating the installer partitionsMake sure you have a good backup of all records on the disk that could be shed, including all the Mac papers. Repartitioning might fail due to drive errors, so having a great backup is necessary.Open Disk Utility, choose the startup disk, and click the partition button.Select the OSXRESERVED partition and also click the “-” switch to remove the partition.Select the BOOTCAMP partition and click the “-” switch to rerelocate the partition.Click Apply to begin the partition removal procedure.Splitting the ISOOpen Boot Camp ISO Converter and select the ISO that resulted in the error.Click “Save…” and also specify a name and also location for the brand-new ISO.After the operation is completed, the brand-new ISO have the right to be used to install Windows via Boot Camp assistant complying with the conventional procedure.Boot Camp ISO ConverterBoot Camp ISO Converter supplies a command choose tool called “wimsplit” to break-up the wim right into parts no larger than 2GB. The WIM format supports split files; once installing Windows, the Windows installer recognizes the separation documents as treats them as a single large file, as long as all the break-up files are in the exact same folder. If you look in the resources folder on the brand-new ISO, you will certainly check out multiple install.swm documents through a number appended on the finish.See more: How To Check Office 2010 Activation Status, And License Type If you favor this write-up and also want to hear more, sign up for our newsletter or follow us on Twitter.