After experimenting, I've successfully removed the installation media immediately after the "Copying Windows Files" stage, IE, as soon as "getting file ready for installation" starts. I've done this on all the computers and suffered no ill effects.
After experimenting, I've successfully removed the installation media immediately after the "Copying Windows Files" stage, IE, as soon as "getting file ready for installation" starts. I've done this on all the computers and suffered no ill effects.