Slow Laptop Performance

[Gman0149]

My laptop over has seen dramatic decrease in speed. I was playing a game fine and the next moment, my laptop turns off. I reboot my laptop and see that the game I was playing at a capped 60 fps was struggling top five fps. I checked to see if there was any thermal throttling, there was none. I think looked at my disk performance and it was at 100%. I did some googling, defraged the hard drive and some other things and nothing worked.So my friend, who is much more tech savvy than me took apart the laptop and saw no visible damage to any parts (we reapplied some thermal paste while we had it apart). He then suggested that my hard drive may have received some heat damage and I should be a new one. So I did and after transferring all of the data, I plugged in the new hard drive and the same problem was happening. We are going to try to do a fresh copy of windows tomorrow but, if I can avoid that, that would be ideal. 

 

My laptop is a lenovo Z50. Any suggestions would be great. 

[Uptivuptiz]

I noticed that your laptop has an AMD GPU. Do you know if that's an APU or a legit GPU (I'm very bad at identifying older AMD models lol). If it's a GPU it might have switched the display output to the integrated graphics instead of the GPU...