Before attempting any BIOS flash, ensure you have stable power. This means a UPS or solar. You don't want a power cut during a BIOS flash or it will result in a bricked board.
I've not seen the links you posted, but typically for a flash process from within a utility in the BIOS - it goes kinda like this:
- Plug in a USB. Any size will do. BIOS files are small. 8GB or more.
- Since most USB drives these days are 16GB or more - as said before - any size will do.
- Format the USB drive. Right-Click on it in Windows and format.
- On completion, copy the ZIP file to the USB drive.
- Right-Click on the ZIP/compressed file and extract it to the USB drive.
- No need to eject the drive since you're going to be using it.
- Reboot the system.
- Go into the BIOS - F2, DEL or some other key.
- Locate the flash utility.
- Locate your USB drive from the utility and navigate (using arrow/enter key) to the location of the flash file.
- Leave it to do what it needs to do.
Knowing the solution doesn't mean knowing the method. Yet answering correctly and regurgitation are considered "learning" and "knowledge".