I'm not sure what causes this issue, I have had a similar issue in the past with one of my keyboards with the letter "c". Thankfully I got 2 PC's and simply switch the keyboards and now the one that had that problem it was "magically cured".
I know that sometimes a key can get stuck is you pressed too hard.
(or let something heavy fall on your keyboard) but that wasn't my case.
This happened to me in multiple occasions with the same keyboard.
EDIT: sorry, I noticed now that is on your notebook/laptop...
I had a friend a while ago brought me a notebook with a similar issue, the only solution was to simply replace
the keyboard, this is something that is actually very easy to do.
Do a search for your (model number - Notebook/Laptop) Keyboard replacement.
After you figured out the part number (of the keyboard) then do a search for THAT part number.
You would be surprise on how much can you save by buying from a "copycat" than from your Notebook/Laptop
Replacing the Notebook Keyboard took me around 10 minutes top.
(and I'm NOT an expert when it comes to Notebooks so is really simple if you follow the instructions)