Universal BIOS Backup Toolkit can identify and back up most known BIOS to a file that can be restored later.
Universal BIOS Backup Toolkit is portable and should be run as an administrator.
All you need to do is choose "read, backup and exit," and that's all there is to it. I was able to backup my BIOS, but there is no guarantee it will work for your BIOS and certainly no guarantee that the backup will work, but the concept and execution are excellent. There are many different motherboards and BIOS, hence the possibility of Universal BIOS Backup Toolkit being wrong occasionally.
The app only has a couple of quirks. One is that the window is not moveable or resizeable, not an issue for most. The other is that a message pops up saying that it's done after reading, but it's under the window you can't move. With most windows, you can close that popup message on the taskbar.