Lenovo Ideacentre A720 stuck om 10 seconds power seving?

But I have this conputer, the Lenovo IdeaCentre A720 that isn't even half a year old and the system is Windows 7 Home Premium

Just a moment ago. I opened my computer and it worked perfectly fine although before my user showed, it had stuff like configuring 100% or something.

So after that i just went on google chrome n talked to my cousin on FB and was scrolling through tumblr until it turned black and it never returned.
I told my mum about it and she unplugged the whole computer and we tried opening it again but now its either stuck on a black screen the 10 seconds power saving or the bluish box at the left corner that says PC for the mode of the monitor.

Please help! Schools abt to start here in our country and my computer is very important in terms of documents! I've got backup but i prefer using that computer since its really fast

"Configuring 100%" is shown on a screen after an update of the Windows 7 has been downloaded and installed.
Try starting in Safe Mode (F5 at power up) to get to safe mode. Go to System Restore to try to go back to before this happened.