Error during boot, "Non Bootable Device" is it USB?
I have seen about half of these systems with a USB stick in the computer and BIOS settings on many newer motherboards is to boot from USB device first, DVD then Hard drive.
As a seriously easy and totally free tip check to see if you forgot to unplug that USB device.
If that's not it check your BIOS settings to what is the first bootable device. If you're like many techo's you'll have 6 drives and might have forgot to label which one has what on it.
But I'd bet you have a USB stick connected or some external drive (USB) and your BIOS is setup to boot USB device first.
If that's not it, keep troubleshooting or ask for help.
Other words: non bootable device found, Non bootable disk drive. Please insert bootable media.
For the life of me I'm not remembering every error message, the secret is the wording. . If I recall, Insert Media is always CD or DVD, Non bootable device is USB and Non Bootable Disk or is that No OS Found is a hard drive error but also if you take the hard drive out and set your BIOS to only boot from hard drive.
The wording of the message is key.