I have good "friends"

So, today I was taking notes in my class and out of nowhere a "friend" of mine slammed my computer shut. at that time, I was downloading some things in the background (Unity and Xarmin Studios) I then opened my laptop up and the screen was black (as usual) and then I had to log in again so I try to type my password in and it just went super slow, and when I did finally put it in it took about 10 minutes to get to my desktop and then I when into task manager eventually and it showed the disk being at 100% utilization, any help?