I bought a new Inspiron 15 5567 a few months ago and have had no issues with it until now. Now when I try to type anything, it acts as if the alt key is pressed (giving special characters such as á or é or triggers keyboard shortcuts e.g. alt tab). I have tried resetting the language, deleting the keyboard driver and restarting the computer with no improvement. Occasionally it will revert to normal for a few seconds but then goes back to being unusable. Any suggestions as to how to fix this?