While the BIOS in IBM's Thinkpad line of laptops may vary slightly between models, some of the most important features remain constant--like the boot options. The Thinkpad's boot options offer a wide range of boot source compatibility for loading programs ahead of your operating system or even restoring it. While an SD card is an unconventional boot source, it can be just as handy as commonplace sources for booting software on your Thinkpad.
Load the program that you wish to boot on your Thinkpad onto your SD card using a USB Card reader--your boot program must contain a file with an ".INI" extension to boot. If you are loading the boot program onto your SD card from a computer other than your Thinkpad, transfer the SD card reader to a USB port on your Thinkpad.
Boot up your Thinkpad--restart the Thinkpad if it is already on--and then watch for the access option for entering your BIOS to appear onscreen. When your Thinkpad's logo appears, hit either the "Access IBM" or the "ThinkVantage" button on your keyboard. Select the "Start setup utility" option on the next screen that appears.
Select the "Startup" option in the IBM BIOS Setup Utility, and then select the "Boot" option on the following screen. Your Thinkpad's boot sources, such as DVD-ROM and Hard drive, will be listed in the order of their boot priorities; the first source to boot will appear at the top of the order.
Use the arrow keys on your keyboard to navigate down to the "USB FDD" or "USB HD" option, and then use the "F5" key to move it to the top of the order. Hit the "F10" key to save your changes and reboot your Thinkpad. The program on your SD card will boot when your laptop restarts.
Proceed with caution if you decide to adjust any other system setting while you are in your Thinkpad's BIOS. Improper setting can cause your system to become unstable.