WDS – Install Image

Hello,
I’ve created a custom install image and loaded it into the images group on the WDS.
I have 2 boot images; one called boot test, and the other is for capturing.
When i boot the PC using F12, i select the boot test and it starts up in the wpeinit prompt.
How do i tell it to startup using this boot image, and then to use the install image to setup the PC?
Thanks.