I think that the F keys are working OK, I can't see a 'lock' anywhere. The strange thing is that there is no wording appearing in the bottom corner on boot-up. I always had a couple of options on my old pc.
Post screen might be set to disabled or something. Try clocking F2 or Del even if you cannot see the text. The BIOS is especially to set the RAM to the advertised speed anyway. You can see the current speed by other means inside Windows. Worry about the BIOS for this only if you confirm the RAM speed is lower. RAM speed might even show on the boot text once you turn on the comp.