I will however tell folk that if I was to reset Windows 10, I'd ignore the F8 key since W10's reset and recovery is done entirely differently from W7 and Dell's way to implement a recovery system.
On most Dells I find the old F8 system is dead after the upgrade to W10. That was not unexpected.
My laptop was originally installed with windows seven. It is a dell studio 1749. According to the manual you press F8 at start up to get to the recovery mode. My question is did windows 10 disable that function key and you have to do the recovery through upgrade and security settings?