Traditionally, ThinkPad BIOS updates have been provided for download in two formats: a Windows .exe installer, and an ISO that can be used to create a bootable CD. The CD version was useful for those who aren't running a Windows OS, or who have a damaged main drive or OS that won't boot.
These days, an optical drive is becoming a rarity - requiring the use of an external drive. Fortunately with recent ThinkPad BIOS updates using a bootable flash drive has become an option. The instructions and tools are included in the Windows .exe. It's necessary to run the 1st stage of the install to access them, so a Windows PC or virtual machine is required.
We'll use a 1st generation X1 Yoga BIOS in this example. Be sure to use a BIOS .exe that matches your laptop model, not the one in this example.
(Most readers will already know how to download the BIOS exe file and will want to skip down to the Installer & Flash Instructions section below. The download instructions here are for 1st-timers.)
The first step is locating the BIOS .exe download. Use the SUPPORT link and enter the laptop's model in the search box:
Select the correct model from the list presented, then Drivers & Software, and BIOS from the Components drop-down.
Then click on the resulting link - BIOS/UEFI in this example - which will bring up something like this:
Select "BIOS UPDATE Utility for Windows... and finally download the .exe offered. Make note of the download location.
Installer & Flash Instructions:
The way the .exe is built it's necessary to run the first stage of the install to be able to access the contained files.
Locate the downloaded .exe and run it. You'll be offered a target folder and the option to browse for a target folder of your choosing. Make a note of where the driver files are going and proceed.
The next phase of the process will ask to actually install the BIOS on the current PC or virtual machine. Don't let it. Un-check the "Install ThinkPad BIOS Update Utility Now" check box and click Finish.
Now you can navigate to the installer files. You should see something like the below. Read and follow the instructions.