Gigabyte BIOS downloads are in the form of an .exc file. The .exc file is a compressed file, as are most downloads, that
are used in order to facilitate easier transmission of files over the internet.
The .exc file is a self extracting file. You must run the .exc file to decompress it. If you don't you will not be using the BIOS file.
You may be just erasing the BIOS, without having the new BIOS ready to install.
I suggest you read the manual on how to recover from a bad flash.