installing windows 7 via usb drive

hi,
i recently bought a new imac which i swapped out the dvd drive for an extra intel SSD hd..

i'm looking for help on how to partition the SSD so that i could run Windows 7 (without the superdrive)..

i installed OSX onto the SSD with a usb flash drive without a problem but when i tried to install windows the same way, bootcamp wouldn't recognise the usb drive..

anybody any ideas?