Did you just purchase a new iMac with a 3 TB internal hard drive? Do you want to install Windows to a partition on that drive using Apple’s Boot Camp software? Those that answered “yes” to both questions recently discovered an unpleasant reality: while modern versions of Windows support large hard drives, the Boot Camp Assistant software required to install Windows on a Mac does not currently support drives larger than 2.2 TB.
Apple can certainly fix this limitation via an update to the Boot Camp Assistant, but thus far no update has appeared and Apple has made no promises on when users can expect one. Thankfully, the fine folks at software developer Twocanoes have created a detailed step-by-step guide to “trick” your Mac and Windows into thinking that the drive within the 2.2 TB limit.
The steps involve creating additional partitions in a specific order so that the Windows installer will recognize the drive layout. Essentially, users must assign Boot Camp to the number four partition, ensuring that the partition does not cross over the 2.2 TB limit. Any space above that limit can be used for an additional storage partition that will be visible to OS X (as well as to Windows once the installation is complete).
Those familiar with partitions and Disk Utility will find the process fairly simple. Those unfamiliar with these concepts will likely still be able to perform the necessary steps thanks to the excellent guide, complete with step-by-step illustrations, although anyone attempting to perform nondestructive partitioning of their hard drive should ensure that all data is securely backed up on other media in the case of an error or drive failure.
We hope that Apple releases an update to the Boot Camp Assistant soon so that these steps may be automated and simplified but, until then, owners of a new iMac with a 3 TB internal drive, or owners of other Macs with upgraded drives larger than 2.2 TB, can at least follow the Twocanoes workaround and get back to running Windows natively on the Mac.