I have a similar problem. I closed my laptop's screen so it should go on stand-by. When I woke it up again, It came into a bootloop. only in my case the loop shows the HP logo and than goes back to black and keeps repeating this.
I think I really tried everything now. Taking out the battery and AC power, Button combinations (Windows+V does nothing, Windows+B Capslock keeps blinking and after minutes and minutes nothing happens), different BIOS boot sequences, tried the following
There is no response on F11 and also not on F9 in BIOS but there is a Restore to defaults option. HD (extended test) and Memory test are OK.
I doubt this boot loop issue has been caused by a virus or malware, my Avast light version did expire on the day it happened, but I also have a MacAfee and till the point it happened they said my files are fine. So I would really like to make a back up of my files before I proceed with further steps like 'Restoring defaults in Bios' or F11 option (eventhoug it doesn't works on my laptop). How could I do that?
I think my Windows version is 8 not 8.1 but not sure, I couldn't choose this option above.
What should I do or did I missed something?
Feel free to ask more info and thanks in advance for your support!