I bet you break something if you remove the older versions. I'd make a restore point before you do anything just in case. There may be programs tied to the older versions. You'll see the same thing for Dot Net Framework and from what I have read it's not a good idea to remove the older entries. You're only talking kilobytes for most of them so is it really worth removing them? If you do nuke the older versions I would be interested to know, for future reference, if it does mess anything up.