Boot but no boot!

HP Probook 6440b, intel core 5, win 10 pro 64 bit. I´m having a real difficulty booting up. The process seems to go o.k. until entering the code/password. When the pin code is entered and enter is pressed the code spots turn white with a blue blackground and nothing happens. After a couple of minutes the whole process starts over again, it doesn´t matter if the codes/passwords are entered or not, the whole process just repeats on and on and on......... When the booting process starts a message says that the "f" menus will be shown if esc is pressed. They do but nowhere is there any help with the booting process. I have tried to find the safe mode boot up but to no avail. Ctrl, alt, del does nothing, neither does rapidly pressing f8 or any of the other f´s not listed on the f menu during the booting process. I don´t have any computer skills to speak of or any reeboot discs so I am at a total loss as to what to do. Help!

Thanks for your post, Ken. Tried Everything and finally was able to access a recovery box by repeatedly clicking f8 during boot up and clicked on the advanced repair options box. What I wanted to do was to do a system restore to a few days earlier, hoping that would solve the boot up problems, what I absolutely did not want was what has happened to me: apparently a whole system recovery instead of the restore I wanted, all apps gone which is going to cost me, both financially and in time in ways I just can´t afford now. I have a list of removed apps (in two colors?) on a laptop that right now, due to the lack of said deleted apps/programs is basically unusable and forcing me to use a very undependable and inferior back-up machine. What to do? My total lack of computer skills (I´m apparently the proof that you can´t teach old dogs new tricks-seems so, anyway) seems to have created, for me, a disaster. Any help greatly appreciated.

Hi Ken,
Sorry about the delay replying, my back-up laptops suck. The 6540 boots up now but all the installed programs and other info is gone and I can´t afford to rebuy and replace said lost programs so I´m basically f@£$ked.