Ken,
I'm not Hu but I know the answer to that.
Mill2000 and XP ptoducts are not the same, so the 3 in 1 patch Hu is talking about is to update only XP products. There is an update for mill2000 also. But if your purchased in the last few months you probable already have the latest stuff. You can go to
http://www.onecnc.com and check the downloads to see.
If I recall you have XP mill pro, right?
Second part:
AFAIK there is never a charge for updates.