New
#31
Have you thoroughly checked that no new options appeared? Normally, after entering the key combinations, screen will flash once for a very brief amount of time and then if you open some menu items, the 'extra' options will be shown.
You can also have a look here -- Help enabling advanced options in AMI bios of VAIO VPCF11S1E
You can try and see if there's any update available for your bios -- AMI | American Megatrends Inc. : AMIBIOS Support
Apart from that, no way that i can think of, as most likely it's been purposely locked by Dell.