Why is my computer performing like ****?

Sebastian Asked: Why is my computer performing like ****?

So my computer just got back from repair and when i am done installing all the drivers for my graphics card etc. (It's a notebook) They replaced the Hdd so i just reinstalled the Graphic card drivers windows updates etc. And when i play Leauge of Legends or minecraft and any other game i experience a huge fps diffrence from before the repair. DONT TELL ME ITS A VIRUS OR THAT I NEED TO UPDATE MY DRIVERS BECAUSE THATS ALREADY DONE!!! Ok, with that said i get half the frames i used to get. Before in Minecraft 100-170 fps. Before in Leauge of Legends 50-90fps
Now: Minecraft: 30-60fps Leauge: 20-50 fps. Again it's not the drivers nor a virus because i just finished installing them and the computer was just reset to factory settings. And i can't use fraps without experiencing crazy lagg. The games a mostly stable with a few lag spikes but are unplayable with fraps which it REALLY wasn't before. I have a decent spec note book. i5 processor nvidia geforce 540, 4 gig ram. (It's an acer aspire 5472g). Also when it broke i dropped a heave book on the keyboard so is it something else hardware related?? They have replaced the Hdd 2 times now the first time it was terrible computer couldnt even start this time i get low frames.