1. Did you install an operating system onto your new build?
If Yes:
2a) Log into your system BIOS and make sure the device you installed the OS to (Hard drive or SSD) is listed first in the Boot Priority.
2b) Make sure there are no other flash drives connected or CDs/DVDs in the optical drive.
2c) Reboot your system
If you have not installed an operating system:
2a) Reboot into BIOS and change the boot priority to list your OS installation media first (USB drive/Optical Drive)
2b) Connect or insert your OS installation media.
2c) Reboot your computer.
If you are trying to install the operating system and you are getting this error, then we need to know what kind of OS installation media you are trying to use and where and how did you...