After MUCH searching and trial and error I have FINALLY found a way to accomplish what I wanted. I hope this helps someone else as well. I followed parts from this guide Note this must all be done from within Windows. http://www.rmprepusb.com/tutorials/win8togo Here are the exact steps I did that finally worked for me. 1: Download RMPrepUSB, install and open. Under 0 at top make sure you have the USB Flash Drive/SD/Micro SD device you wish to use selected!! Select the following options. -Under 3-Bootloader Options: WinPEv2/WinPEv3/Vista/Win7 bootable [BOOTMGR] (CC4) -Under 4-Filesystem and Overrides: NTFS radio button and check "Boot as HDD (C:2PTNS)" -Click on bottom left "6 Prepare Drive" 2: Download GetWaikTools and open (no install required) http://www.rmprepusb.com/tutorials/getwaiktools Uncheck "Waik Tools for Windows 7" Check "Waik Tools for Windows 8" Verify "Download to AppDir\Waik_*" is checked Click "Download" This will create a new folder in the directory you launched GetWaikTools.exe from. Open a command prompt with administrator rights and navigate to the newly created folder and then into the correct architect type (32bit or 64bit) that matches the Windows 8 installer you'll be using. Assuming that your Windows 8 ISO is mounted at E: and the USB drive has the drive letter of F:, type the command: "imagex.exe /apply E:\sources\install.wim 1 F:" (Without quotes) Hit Enter This will take a very long time (1 hour or more) depending on the interface and speed of the media. Once it completes, type: "BCDBOOT.exe F:\Windows /s F: /v" (Without quotes) Hit Enter If that fails it may be because you have an EFI Windows system, in which case try the following command: "BCDBOOT.exe F:\Windows /s F: /f ALL /v" (Without quotes) Hit Enter Reboot your Mac and hold the alt/option key, you will now see the device as a bootable option. Arrow over to it and hit enter. It will run through a device/hardware detection process that can take a long time initially but after that completes you have a fully functional version of Windows 8 running from a USB or SD slot attached flash device! ========================================================== Original Post: I can install OS X to a SD card in the SD slot and boot it without issue. I want to do this for Windows 7 or 8 if there is any way possible. I can dual boot my 13" 2011 MBA using Bootcamp and the internal SSD of course and I even used Disk Utility to clone the Windows volume to the SD card but I cannot select it as a boot device by holding down the ALT/Option key on start up, it just does not list the SD "drive" as an option to select to boot from when it has Windows on it, but does show it as a valid option when it has OS X on it. When I run the Windows install on the MBA, again I cannot see the SD "drive" as an option and am wondering if there is any driver I can load to enable support of the SD card for Windows at that point? Is there any creative way whatsoever to boot this MBA from a SD "drive" using Windows? I don't use Windows much and hate wasting the space on my SSD to keep the Bootcamp partition there for the limited use. The results in a regular chore of blowing away the Windows Bootcamp volume in order to free up space in a pinch only to have to reinstall Windows via Bootcamp down the road for a need that comes up. I would LOVE to be able to use this 64GB Micro SDXC Class 10 card I have and stick it into the SD slot and boot up into Windows for the limited usage that comes up for my job and then remove it and store it away when not in use. I'm wondering if there's a way to accomplish what I want using some of the methods Hackintosh folks use to make non-Apple drives bootable. Maybe somehow making the FAT formatted SD card usable by the EFI?