Failed BIOS update. HELP!

So i tried to do a bios update on my optiplex 390 pc. So i created a bootable usb drive (on another pc because i can't access windows because my hard drive isn't found for some reason) by following these instructions: https://www.dell.com/support/article/us/en/19/sln143196/how-to-create-a-bootable-usb-flash-drive-using-dell-diagnostic-deployment-package-dddp-?lang=en

So i did that and then downloaded the optiplex 390's latest bios and moved the .exe file into the bootable usb drive. I then put the usb in my optiplex and booted into the drive and shows me this. Idk what to do, please help!!