Cannot Boot To BIOS Setup (F2) or One-Time Boot Sequence Options (F12)

Instead of pressing F2 over and over be patient and press F2 then F12  wait at least 1 second between presses.

If that doesn't work disconnect hard drive data cables and wait for the error.

F12 booting doesn't work when secure boot is on.

F2 then F12 F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12  F2 then F12 

I had the same problem and saw many other threads with exotic complex solutions. Then, by accident, I found the easiest fix. Did you ever hear of a function lock key? I didn't either. Think of it as a capslock key for the function keys. It is directly to the right of the F12 key on a MS keyboard. If is labeled F Lock

If F2 and F12 are not you into BIOS, you probably accidentally hit the F Lock key - easy to do as it is next to F12.  This changes the function of all the function keys which you can program for other actions. 

To restore the function keys to their base configuration, tap the F lock key once, then try booting again while tapping the F2 or F12 keys as you normally would.

To help you remember this trick you can just consider the F in F lock as referring to another adjective of your choice.

Cheers!

Tomster4

Thanks for this important info. I will not this for future reference.

I found out in my case, I had a third monitor that was turned off, where the Dell logo shows when powered on. Since it was powered off, I could not see the message for the F12.

Thanks again.