Dell XPS 13 L322X :: Stuck After Logo Screen - Win 8 OS / No Update Done

I have an XPS 13 (L322X)  running Windows 8. Yesterday I turned it off with the proper "Shut down" function. Willing to restart it, it never did.

Similarly to the post but without Windows 8 update (nor of other software)!

"I see the Dell logo, then it goes dark (but the screen is on, i can see LED glow at the edge of the screen), nothing happens anymore. If I hit the ESC or Return key I see a progress bar near the bottom of the screen and 'F12 Boot Options' at the lower right corner. There is no indication in the progress bar, so I do not know whether it is showing 0% or 100%. If I do Ctrl-Alt-Delete the laptop starts all over again, Dell logo, dark screen, hit any key, progress bar... and that's it. Hitting the Power button does the same thing, whether I hit it once or hit-and-hold."

I also tried the F12 key, but nothing moves after the "on hold" progress bar. I cannot disconnect the battery, yesterday I unplugged the power adapter and let it run out of battery, restarted but nothing changed.

The only thing I can do is with F2 entering the BIOS but since I am not a tech, I didn't trust to make changes there.