From what I can find it should be the F2 key to access the BIOS. Make sure the computer is completely turned off. Hit the power button & then start pressing & releasing the F2 key repeatedly until you see the BIOS or the windows start screen. If you see the windows start screen then turn it off & try again. If it still fails after 2 tries then I would find a windows program that can detect keystrokes & make sure your F2 key is actually functioning, as it could be a hardware problem: broken key.