If you see the error message The Windows ISO file is too large while using Boot Camp Assistant on a Mac PC, read this post. We will show you how to troubleshoot the issue the right way. Boot Camp Assistant has been Apple’s go-to solution for installing and running Windows on a Mac computer. It creates a dual-boot setup, enabling users to choose between macOS and Windows while starting their computer.
However, Boot Camp is no longer supported in Apple’s Silicon-based Macs and is only shipped with Intel-based Macs due to which, it is not receiving any updates from Apple. Users have been reporting various Boot Camp issues, such as its inability to handle Windows 10 installation files, ISO-mounted errors, system file errors, and so on. One such error message that a few Mac users have reported is: The Windows ISO file is too large. The complete error message reads:
The Windows ISO file is too large – Boot Camp Assistant creates a [X] GB installer partition which will contain the files present on the Windows 10 ISO as well as the Boot Camp Support software. The supplied ISO is too large to fit on this installer partition.
The Windows ISO file is too large Bootcamp error [Fix]
To fix the Boot Camp error message The Windows ISO file is too large, use these solutions:
- Free up disk space
- Split the ISO file
- Download a smaller Windows ISO
- Create a Bootable USB Drive
Let us see this in detail.
1] Free up disk space
While preparing the disk for installation, Boot Camp creates 2 partitions (both formatted as FAT32/exFat), one for keeping the installer ISO and one where Windows will be installed. The installer ISO contains install.wim, the largest file in this folder. If the size of install.wim exceeds the size of the installer partition Boot Camp has created; you may likely encounter the error.
Make sure you have enough free disk space to handle the Windows installation files. Delete unnecessary files or move them to an external drive to create more space on your Mac. Once you have enough free space, unmount the Windows ISO file from your disk and then run Boot Camp Assistant again. Alternatively, you may use Mac’s built-in Disk Utility or a third-party disk partition tool to extend the partition size in Boot Camp.
2] Split the ISO file
Another workaround is to split the downloaded ISO into smaller parts. This would help if Boot Camp has formatted the partition as FAT32. The file system used for the Windows partition is typically NTFS; however, Boot Camp on older Macs formats the disk partition as FAT32. FAT32 has a file size limitation. The maximum file size supported by the FAT32 file system is 4 GB.
There are many third-party software (such as Boot Camp ISO Converter) that can help you split up the install.wim into smaller parts. As long as all the split files are in the same folder, the Windows installer recognizes them and considers them as a single ISO that can be used with Boot Camp Assistant.
3] Download a smaller Windows ISO
You may try using another ISO which is less than [X] GB in size (where [X] refers to the size mentioned in the error message). Microsoft offers ISO files that include multiple editions of Windows, allowing users to choose the specific edition and language during the installation process. ISOs that contain more editions of Windows may have a larger file size than ISOs with fewer editions. You may check the file size of the ISO file before downloading it from the Microsoft website.
4] Create a Bootable USB Drive
Instead of using the ISO file directly, you may create a bootable USB drive and use the Boot Camp Assistant to install Windows from the USB. You just need to make sure the USB drive has enough capacity to accommodate the Windows ISO file.
Plug the USB drive into your Mac. Then open Boot Camp and choose the Create a Windows 10 or later install disk option. Select the Windows ISO image and the USB drive, and follow the on-screen instructions to create the bootable USB. Once you have the bootable USB ready, you may use it to install Windows on your Mac.
I hope this helps.
Read: How to fix Windows install.wim file is too large for USB flash drive.
How do I fix Boot Camp installation failed?
If you encounter an error or failure during the Boot Camp installation process, make sure your macOS is up to date and it meets the specific system requirements for the version of Windows you are trying to install. Also, make sure you have enough free space on your Mac’s hard drive to create a Windows partition. Update your Boot Camp to the latest version and retry the installation.
How do I remove Boot Camp from my hard drive?
Open Boot Camp Assistant. You will see all the installed partitions on your Mac. Select the desired partition and click the Restore option. Confirm the removal, restart your Mac, and optionally uninstall the Boot Camp drivers in Windows. If required, use Disk Utility to reclaim the space previously occupied by the Windows partition.
Read Next: Boot Camp could not switch between Windows and Mac OS.
