This problem has been pestering me for a while now. I upgraded my Windows 7 machine to Windows 8 which is not that bad like most people say a few months ago. Now after testing the OS and running into some minor compatibility issues I decided to downgrade and revert back to Windows 7 just for stability. When I was still using Windows 8 I can still access the BIOS menu be it a bit more complicated that it used to but now that I have Windows 7 back, whenever I press F2 on start up to access my BIOS nothing happens! It just gives the OS selection screen. Is there anyway I can restore my BIOS? It's a Phoenix BIOS by the way.
Your OS doesn't have any access to the BIOS, so that definitely isn't the issue. Something else must have happened on the way. Did you try mashing the F2 key as soon as you turn the PC on? Maybe your system reset the window during which it's possible to boot up into your BIOS settings (which shouldn't be possible, but maybe it's just booting up faster now), and that's why you have the problem. Otherwise, there's no way to change BIOS settings without actually booting up the settings screen.
At first that's what I thought too, the OS doesn't really have access to the BIOS but somehow I think it did something. Although my computer boots really fast, it still allows me a few seconds to press/mash F2 and I know I hit the key because Windows doesn't boot out right, instead it takes me to some advance OS options. I tried pressing F11,Delete and all other F's every boot up but it just doesn't go to the BIOS menu but instead takes me to advanced OS options.
That's weird. Windows does not have access to BIOS, however. It's done that way on purpose, so no malware can rewrite or mess with it. So Windows doing anything is definitely not possible. Try mashing delete and insert instead of the F keys, it's possible that one of them is triggering the advanced boot options.