Tomtom have got a new piece of software that you can download to your pc and when you connect your tomtom rider to your pc it automatically shows you the available downloads and you are then asked if you want to proceed.
Just for your info there is now a new version 6.10 of the actual tomtom rider flash software which is really nice and FREE to all. try it here http://www.tomtom.com/plus/service.php?ID=17