You may try disabling the fast boot options. If such options are not enabled you can use the power button recovery as a workaround to enter BIOS.
Joe, it seems that the "fast boot option" is enabled, although I see a screen which asks F2, F7 and F10. But again it doesn't accept any of those function keys from my wireless keyboard and therefore I don't get into BIOS anymore at all.
And I don't understand what you mean by "use the power button recovery as a workaround to enter BIOS". Could you explain please?
I have a wireless keyboard. When I try to run Mint live I have to have the USB flash inserted in a front port. I cannot get into the BIOS with the flash inserted into one of the back ports.