For any of you visiting Windsor, which is only about 15 miles from me, the best time of year to visit is the Autumn as it has slightly less tourists then. The cost of parking is horrendous, however if you are driving go towards Old Windsor, that is just passed the railway station, on the left is a car park. Go to the very end of the car park opposite the playing fields and you can get cheap parking about £3.20 for four hours. If you go on a Sat/Sun it is free. There is a very occasional mini bus that takes you into the centre otherwise you have a 10 minute walk on the flat into town, then a hill up to the Castle. Buy your castle tickets online to avoid the cues.