Are you sure you pressed F8 at the right time? You should definitely be able to boot into safe mode as sim03 suggested and that sounds like the best hope at this point.Quote from CaptainObvious:
Have tried the F8 key, nothing. Ctrl and Esc. Nothing. Ctrl and windows key, nothing. I need to be able to get into the control panel to change the display and I've yet to find a way to access that.
Just start pressing it as soon as your PC reboots, dont wait for the Windows display to appear.