Computer slow after transporting it?

I have a Lenovo Y510p laptop and the other day I brought it over my friends house to watch a movie. When I got back home something was wrong. It is much slower in pretty much every aspect. Browsing the internet, playing games, etc. Judging by what I've read on the internet some people think that the sudden change in performance could mean something is loose internally due to me moving the laptop. I already took off the case and checked within but I really have no idea what i'm looking for. Any thoughts?

There has been a change in some settings when you changed the environment (by going to your friend's house). Something on the network settings has changed. Or worst case, you now have a virus making your computer a zombie or bot.
That is all that can be guessed since you have not told about Internet connections or networking setups and usage at your friend's or your house.