Bootcamp (i know i know..... but this is different)

i have searched high and low for an answer so finally have to ask,
I want to dual boot, Mountain lion/windows 7. i have read several guids such as this one http://www.pcworld.com/article/249059/how_to_install_boot_camp_and_run_windows_on_your_mac.html

I have successfully created an install disk (flash drive), downloaded support software and partitioned. every guide i have read now says to click "start installation" but i have no such option, this is all i have

although it says remove windows i have not installed windows yet.

any help would be fantastic and i apologise in advance if this has been asked before but i could not find the answer

David

Quad5Ny said:

You've partitioned and created the thumb drive? Then all you need to do is restart your Mac and Hold down the "Option" key before the grey Apple logo.

Holding down Option will give you a list of all bootable disks (including the flash drive if its plugged in).

Click to expand...

Thank you for the help, i have done that and the windows bootable drive shows up but then i get a "No bootable device found"

admittedly i am using a 32gb SD card in a usb adapter but surly thats just the same as having a memory stick?

thanks again