Installation USB key issue

" When the message appears saying that the install or update is complete, it will automatically initiate a reboot after 10(?) seconds. You must remove the USB flash drive before the reboot starts or else the system will continue to boot off the flash drive...."

I (Rosie) still am not sure when to pull the key for sure. ** A nice Stop and Prompt to say when to remove the USB... and hit enter to continue wbg.**