Ok I've tried everything except change my hard drive on my laptop... I've tried powering on and off, the f8 f11 and The f5 key. I Have a dell inspiron 1750 window 7 with a windows10 upgrade... Also the only function key that is working is the f2 and f12... I even checked the hard drive for cracks since it was dropped... I lost my installation disk due to moving so I can't use that! Can someone Please give me a solution to this head ache.... Thanks; jeannieb56