Please help - problem installing Win7 with BootCamp

Hi
I am trying to install Windows 7 on my MBA using Bootcamp.
I used Bootcamp Assistant and got as far as partitioning the drive and starting the Windows installation process (selecting which partition to install to), and then cancelled out of the installer.

The machine then rebooted itself and is now just showing the message: "No bootable device -- insert boot disc and press any key".

What can I do? Any help would be hugely appreciated.

Thanks.

 

Don't worry I think I've sorted it. For some reason the installer didn't install properly to the USB drive. Running Bootcamp again and hopefully it works this time.