Boot Camp: Frequently asked questions about installing Windows 8

General installation questions 

What is Boot Camp 5?
Boot Camp 5 is not a release of OS X software. Rather, it is a release of the Windows Support Software (drivers). You will need to use this software on your Mac with Windows 8 or Windows 7. For more information on Boot Camp 5, see this article.

Which Macs support Windows 8?

• MacBook Air (Mid 2011 or newer)
• MacBook Pro (15-inch and 17-inch, Mid 2010)
• MacBook Pro (Early 2011 or newer)
• Mac Pro (Early 2009 or newer)
• Mac Mini (Mid 2011 or newer)
• iMac (27-inch, Mid 2010)
• iMac (21.5-inch, Mid 2011 or newer)

For more information, see this article.

What are the System Requirements for Windows 8?
Please see this article.

How can I install Windows 8 on an eligible computer?
Use the Boot Camp Assistant. The assistant will partition your internal hard drives and install Windows 8. For more information on Windows 8 installation, see the Boot Camp Installation & Setup Guide.

Can I use an upgrade from Windows 7 to Windows 8?
Yes. Download and install the Boot Camp 5 Support Software before attemping the upgrade by using the Boot Camp Assistant in OS X Mountain Lion v10.8.3. Alternatively, you can manually download the Boot Camp 5 Windows Support Software here.

When I do an upgrade install from Windows 7 to Windows 8, an "Uninstall USB 3.0 eXtensible Host Controller Driver" message appears. What do I do?
Do not click on Uninstall. Click the back button and Cancel the upgrade. Download the Boot Camp 5 Support Software by using the Boot Camp Assistant in OS X Mountain Lion v10.8.3, or click here to download them. Then, try the upgrade again. See this article for more information. 

After upgrading from Windows 7 to Windows 8, Thunderbolt devices are not being recognized when I connect them. How do I fix this?
Disable the Windows 8 Fast Boot feature to allow Thunderbolt devices to be recognized. See Boot Camp: Thunderbolt devices not recognized after Windows 8 upgrade for instructions.

Is there an OS X version requirement to use the Boot Camp Assistant to download Boot Camp 5 Support Software?
You need OS X Mountain Lion v10.8.3 or later installed to download the Boot Camp 5 Support Software (Windows drivers) using the Boot Camp Assistant. After upgrading, click the Go menu and choose Utilities. Then, open Boot Camp Assistant and follow the onscreen instructions. You can download the Boot Camp Installation & Setup Guide.

Is there a download of the Boot Camp 5 Support Software if I'm not using OS X Mountain Lion v10.8.3?
Yes, you can download the Boot Camp 5 Support Software here.

How do I use the Boot Camp 5 Support Software I downloaded from the web page?

1. The download file is a .zip file. Double click it to uncompress it.
2. Double-click the Boot Camp disk image.
3. Copy the Boot Camp and "$WinPEDriver$" folders to the root level of a USB flash drive or hard drive that is formatted with the FAT file system (see question below for steps on how to format). 
4. Install Windows, leaving the flash or hard drive attached to the USB port of your Mac.
5. Installation of the drivers can take a few minutes. Don't interrupt the installation process. A completion dialog box will appear when everything is installed. Click Finish when the dialog appears.
6. When your system restarts your Windows 8 installation is done.

Note: If the flash drive or hard drive was not attached when you installed Windows and was inserted after restarting into Windows 8, double-click the Boot Camp folder, then locate and double click the "setup.exe" file to start the installation of the Boot Camp 5 Support Software.

How do I format USB media to the FAT file system?
Use Disk Utility to format a disk to use with a Windows computer. Here's how:

Important: Formatting a disk erases all the files on it. Copy any files you want to save to another disk before formatting the disk.

1. Open Disk Utility.
2. Select the disk you want to format for use with Windows computers.
3. Click Erase, and choose one of the following from the Format pop-up menu:
   
   • If the size of the disk is 32 GB or less, choose MS-DOS (FAT).
   • If the size of the disk is over 32 GB, choose ExFAT.
4. Type a name for the disk. The maximum length is 11 characters.
5. Click the Erase button and then click Erase again.

Which versions of Windows are supported with Boot Camp 5?
64-bit versions of Windows 8 and Windows 7 are supported using the Boot Camp 5 Support Software. If you need to use a 32-bit version, you need to use Boot Camp 4 Support Software, and you must use Windows 7. 32-bit versions of Windows 8 are not supported via Boot Camp. For a complete list of Windows OS support, click here.

Model-specific Questions

I receive a "Free up space on Drive C" message when I try to do an upgrade install from Windows 7 to Windows 8 on my MacBook Air (11-inch, Mid 2012).  Why am I seeing this?
There is not enough free space available to do an upgrade install with the 64 GB SSD configuration. Delete the Boot Camp partition and do a full install instead. See this article for more information.

I see a black screen or distortion when I install Windows 8 on a MacBook Pro (Retina, 13-inch, Late 2012). How do I fix this?
The Windows 8 installer does not contain the correct graphics driver for your computer. You'll need to attach the USB media that contains the Boot Camp drivers during installation to address this issue. See this article for more information.

The brightness controls keys (F1 and F2) won't work on my iMac (Mid 2011). How do I control the brightness?
Use the Settings Charm to control screen brightness. See this article.

My MacBook Air (Mid 2012) will not start Windows 8, or displays VGA graphics when it stats up. How can I fix this?
Your MacBook Air (Mid 2012) needs an EFI Firmware update to address this issue. Download and install the MacBook Air EFI Firmware Update 2.6.

I see a "Windows 8 is not supported on this Mac" message on my Mac. Can my Mac run Windows 8?
For a complete list of Mac computers and the Windows operating systems they support, click here.