The at key on my laptop won't work, the one where you hold shift and press for the at the " comes up and when I don't hold and press shift this comes up ' so I find it hard when putting in email adresses.

Make sure your keyboard layout is set to default. Also set to "english". It sounds like it might have changed some where along the line. Look there first.

What happens when you press Shift and 1,3,4,5 etc, does it affect all shift/numbers?