I have refrained from answering your request for help because I am a Windows computer technician, not a Apple/Mac tech. But it has been three days, so since no one else has answered, I'll try. '''Pointer is also randomly jumping around whilst writing''' You say that you have nothing touching the touchpad, but I've found that this will happen to people as they are typing because their palms are touching the touchpad. '''the pointer does not drag mail/tab around desktop''' You will have to explain this better so I can understand, possibly including screenshots. Exactly what are you pointing at, and exactly are you trying to drag? The Thunderbird window? Are you able to click and drag other program's windows around the desktop? [https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem How do I create a screenshot of my problem?]