What interface does a SD Card use? I looked at the Wikipedia article and they mention SDIO. However this seems to be just for non data transfer. Is the interface usb like? Completely usb? If it is not usb, can windows be installed and booted off it (The aleutia computer (just randomly browsing web) supports booting xp off a compact flash card)?
Whether Windows can be booted from SD card depends on whether the computer BIOS or UEFI supports booting from SD. The details of the interface are unimportant (it includes SPI).