Install/Run Windows 7 off SD Card on 2010 13" MacBook Air

Using a virtual machine you can build the system on the local drive then move the entire virtual over to the sdcard and run it from there. I currently do this with USB pen drives for the same reason. I test different applications and do not want several different versions on my harddrive. Yes they are slower but still work fine after they boot up.

Windows Setup will not permit you to install to media other than an IDE or SATA connected hard drive, regardless of what drivers you have. Therefore, it is not possible to install and boot a full Windows 7 environment from an SD card.

If you must boot Windows from an SD card, consider using Windows PE, a stripped down version of Windows 7 designed to boot from USB and optical media. You can use use command-line tools from Microsoft or third-party graphical tools to build a customized image with the drivers and programs you need. Please note that you may need to use another computer or virtual machine running Windows to get everything set up properly.

Windows PE is available free of charge to anyone with a valid Windows license as part of the Windows Automated Installation Kit.