Using an External HDD as a bootable Windows Disk I want to use my external HDD as a bootable USB drive so I can install Windows 7 via bootcamp but I am having trouble getting bootcamp to just use one partition of the drive.

When I get to the stage in Bootcamp where a bootable drive is created, Bootcamp teLls me it is going to delete all the data on my HDD, this is not what I want, I just want Bootcamp to use one of the partitions on the HDD to create the Bootable disk, but it doesn't give me that option.Does anyone know a know a way to solve this problem?
The partition has to be formatted NTFS. Special set ups like this are better done manually, not with bootcamp.

Format the partition NTFS, then startup with your windoze disk and try to install it to the USB drive.