In your bios in Advanced Setup. Click the Advanced tab then, PCH Storage Configuration
Verify SATA controller is set to - Enabled
Set SATA Mode to - RAID
Go back one screen then, select Onboard Device Configuration.
Set SATA Mode Configuration to - SATA Express
Go back one screen. Click on the Boot tab then, scroll down the page to CSM. Click on it to go to next screen.
Set Launch CSM to - Disabled
Set Boot Device Control to - UEFI only
Boot from Network devices can be anything.
Set Boot from Storage Devices to - UEFI only
Set Boot from PCI-E PCI Expansion Devices to - UEFI only
Go back one screen. Click on Secure Boot to go to next screen.
Set Secure Boot state to - Disabled
Set OS Type to - Windows UEFI mode
Go back one screen. Look for Boot Option Priorities - Boot Option 1. Click on the down arrow in the outlined box to the right and look for your flash drive. It should be preceded by UEFI, (example UEFI Sandisk Cruzer). Select it so that it appears in this box.