After this guide you should be able to boot from USB on an old IBM Thinkpad T40 or equivalent. This assumes there is a problem with the boot menu not containing your bootable USB drive; or just not understanding how to boot from USB on these devices.
BIOS Setup
- Start up your T40 and press F12 on the keyboard to enter the boot Menu
- Arrow down to
- Go to Config -> USB -> USB BIOS Support
- Change this to Enabled
- ESCx2 to return to first menu
- Go to Startup -> Boot
- In this screen you can only have 8 items in your Boot Priority order. If you have 8 and you attempt to add either +USB HDD or another device it will beep from the motherboard. So remove a device from the Boot priority order, Legacy Floppy Drives is not likely important so I removed that one. Press the x key on Legacy Floppy Drives to exclude that. Then press x on +USB HDD to enable that one. Then elevate that device to the top using F6. I placed it 3rd so that I can use the boot menu to load it.
- F10 to restart, press Yes to confirm save.
On Restart
- Press F12 to return to the boot menu
- Press your USB Flash Drive to boot from the device