There are two buttons on the top left corner of the notebook computer, one is power the other (smaller one) is Novo button.
The smaller Novo button will allow you to access BIOS if used to power up the notebook from a power off state. When powered off, use the Novo button to power on the notebook and then choose enter bios from options presented.
I do not work for Lenovo, I only provide suggestions based on my personal willingness to help others. All advice and comments are based on my experience, and do not reflect Lenovo policy, terms or conditions.