What does the "Access IBM" button do on old IBM laptops?
What is the function of this key?
It provides access to IBM specific system utilities and information. It was often tied into specific software that helped with getting support and help preinstalled into the system, and acted as a shortcut.
The exact labelling and colour of the button changed over time and ownership of the ThinkPad line. Originally it was grey and labelled ThinkPad, IBM later made it blue, and called it the Access IBM Button. Lenovo relabelled it as ThinkVantage when they bought over IBM's PC business.
The exact help and support options, and tools varied with model and generation, and acted both as a tutorial system as well as provided quick access to IBM and ThinkPad specific tools. In many cases, there were also alternate means to access these tools through the start menu or desktop
One example of the use of this button would be to trigger the recovery environment to restore a PC to its original/factory state easily. Many machines used this key to either trigger a restore partition/environment. Some older machines also used this as a way to interrupt normal boot and get into the BIOS.