What are your system specs? Does your system have a UEFI bios and is your system in UEFI or legacy mode? You can't just "press" F8. You have to start mashing F8 repeatedly, as fast as you can, and not stop until the advanced boot menu appears. I mean actually start doing that maybe even before you hit the power or simultaneously. Some systems require Shift+F8, so try both. Barring that working, you might be able to access the boot menu using the windows installer media if you created installer media and upgraded from that. If you upgraded from within windows update, you're screwed in that regard.
You might also try unplugging your boot drive, power up until you get the no bootable disk screen, powering off, reconnecting your drive and attempting to boot again. Also, you would be wise to possibly also try resetting your bios to default settings and rebooting. Don't try each thing at once, go one step at a time.
Enabling or disabling Compatibility support module (CSM) in the bios may work as well.