....if you "made some changes in the bios" previously, which button did you press at that time? If it was the F2 key, have you tried pressing the F2 key repeatedly, about twice per second....or maybe just hold it down?
Remember also, if the computer has Windows 8 pre-installed, it can get dicey using the traditional F key access items. You may need to open the "Charm Bar" by pressing the Windows Key+C simultaneously, then selecting "Settings", etc. See the link below:
And just a thought here, if you changed USB related settings in the BIOS, such as disabling "Legacy Support", AND you're using a USB keyboard, you may need to use a ps2 keyboard to access the BIOS settings.
Hope this helps.
hy guys .. does someone how i can acces my bios on an samsung ? it haded wind 8 and i wanna instal wind7, but after i've made some changes in bios when it restarted said to press f2 for setup (which does nothing just restarts the computer) and press f4 for recovery... i've done that too but after the recovery ends it enters on the same screen ... and windows doesnt boot... i have the same screen which says all boot options are tried and to press f4 for recover with factory image or any other key for next boot loop iteration ...and if i do de recovery again i have the same result ... how can i enter bios now ? please help...