There's also a train from Kingston to Twickenham, though -- or at least there used to be when I was having antenatal appointments with DS. So you hop on train at Kingston, train to Twickenham, cross over platform and get on train to Windsor. Unless they've scrapped that train in the meantime.
Don't think there is a bus from Kingston to Windsor. Would take ages avoiding the motorways. I drove to Windsor from Kingston a few weeks ago, took 55 minutes avoiding the motorway. Dread to think how long bus would take. You might be better getting the train.
I am flying into heathrow very early in the morning with two children and I would like to visit a friend in kingston before going to windsor. I see there is a bus / coach from heathrow to kingston. x26. is that a normal bus or a coach? does anybody know?
and then later, is there a coach from kingston to windsor. i know there are trains but you always have to change. when i have children and i am carrying all the bags, i just like to sit down and sit tight 'til we get where we're going!