Hi @idokopat
Go to http://www.keyboardtester.com/
Launch keyboard tester to check your keyboard keys.
Monitor if the Win Key is activated,
If so, it could be due to stuck key and
Try remove the keyboard from the laptop and see if the problem persists.
Clean up the keyboard from dust and use an eraser to erase the contacts of the LVDS cable... reinsert and try again.
Be warned on the delicate plastic locking mechanism locking the lvds cable of the keyboard.
https://d3nevzfk7ii3be.cloudfront.net/igi/4oYZiIStuHApJTuF