This is an update for LEGO NXT software 2.0 - If you are using LEGO NXT software 1.1 or earlier, you need to upgrade to the latest software first.
This update primarily resolves issues with Flash 10.1 and compiler issues, for a full fix list, please see the read me file in the download.
This does not upgrade your NXT version to NXT 2.0
If you are not sure of your NXT version, please contact Tech Support at: http://mindstorms.lego.com/en-us/support/default.aspx