Hi Chris, depending on your BIOS version, there are sometimes many options to be changed for you to be able to boot form a flash drive . . .
Make there changes (if available) and see if your system boots from the installation media - don't worry, you can always restore defaults if that does not work . . .
Insert the Bootable Installation Media, then go into your BIOS and make the following changes:
- Disable Secure Boot
- Enable Legacy Boot
- If Available enable CSM
- If Required enable USB Boot
- Move the device with the bootable disc to the top of the boot order
- Save BIOS changes, restart your System and it should boot from the Installation Media