IBM ThinkPad® T40 Series Service And Troubleshooting Manual page 22

Some of the topics in your help system contain brief video clips that show
you how to perform certain tasks, such as replacing your battery, inserting a
PC Card, or upgrading your memory. Use the controls shown to play, pause,
and rewind the video clip.
Note: If a bootable device is attached to the computer, and the boot priority
xx
®
ThinkPad T40 Series Service and Troubleshooting Guide
of that device is higher than IDE HDD, the computer boots from that
device.