Installing a new OS—whether it's OS X or Windows—gets a bit tedious for systems administrators, especially after hundreds of installs. While deployment technologies, such as DeployStudio and SCCM, exist to ease the workload, sometimes for a one-off or family member's computer, it's nice to have a simple solution.
Arguably, it doesn't get much simpler than a USB flash drive-based installer. Tiny and lightweight, nothing beats the portability of a flash drive! Plus with the larger storage capacities available, it's a cinch to store multiple operating systems on one drive, as opposed to carrying one CD/DVD for each flavor of OS.
In light of recent initiatives, such as BYOD taking charge, many businesses are offering Macs to its employees as alternatives to dedicated PCs. And while OS X is quite capable of performing on its own—depending on the type of business—a reliance on some Windows-only apps might find IT supporting both operating systems.
It's with these growing heterogeneous or hybrid environments in mind that the benefit to creating a bootable USB drive—capable of installing Windows on either Apple or PC hardware—really shines. So, take a moment to review the requirements before creating your drive.
- Apple computer or PC running Windows 7 or newer
- Windows DVD or ISO
- 8 GB or larger USB flash drive
Now, let's go over the steps to create a Windows installer flash drive from scratch directly from Windows, not OS X.
- Insert the DVD into the media tray, and connect the USB drive to an available USB port. If using an ISO, extract the contents to a folder in the root drive (Figure A).
- From the command line, enter "diskpart" to access the disk partition utility (Figure B).
- To find the disk's volume, enter "list disk" and note which disk matches the size of the USB drive (Figure C).
- Now, enter "select disk #" to select the correct disk (Figure D).
- The drive will need to be cleaned before configuring. Type in "clean" to remove all formatting from the drive (Figure E).
- Next, enter "create partition primary" to create the partition that will hold the install files (Figure F).
- Once complete, enter "active" to enable the partition (Figure G).
- To assign the drive a mount point, enter "assign letter= X," whereby "X" identifies an available drive letter not currently being used (Figure H).
- Next, we format the drive. Type in "format fs=ntfs quick" to format and assign the file system used by Windows (NTFS). The "quick" switch is optional, however, it speeds up the process considerably (Figure I).
- Type "exit" once the process is complete, but don't close out of CMD just yet (Figure J).
- Navigating to the directory where the Windows install files exist, change the CMD path to the Boot directory and enter the following command:
bootsect.exe /nt60 "DRIVE_LETTER"
- Upon entering the command in step #8, the USB drive will be partitioned and configured to function as a bootable device to load Windows (Figure K).
- The only thing left is to copy the installer files directly over to the USB drive (Figure L).
Depending on the speed of your drive, the copy process could take 15+ minutes. However, once it's complete, safely eject the drive, and your bootable Windows installer USB will be ready to install Windows via Boot Camp, Parallels, or Fusion on the Mac.
This process will also work to install/upgrade Windows on existing PCs. Even bare-metal hardware is supported natively.
- Pro tip: An even easier way to create a bootable USB Installer for OS X Yosemite
- The complete guide to a Windows 8 clean installation
- ZDNet: How to turn your Windows 10 upgrade files into an ISO disk image
- ZDNet: How-to: Burn your Windows 7 .ISO to DVD disc
Jesus Vigo is a Network Administrator by day and owner of Mac|Jesus, LLC, specializing in Mac and Windows integration and providing solutions to small- and medium-size businesses. He brings 19 years of experience and multiple certifications from several vendors, including Apple and CompTIA.